By Mira Grant

Read by Christine Lakin

Formats and Prices


This item is a preorder. Your payment method will be charged immediately, and the product is expected to ship on or around November 24, 2015. This date is subject to change due to shipping delays beyond our control.

From New York Times bestselling author Mira Grant comes the final book in the terrifying Parasitology series.
The outbreak has spread, tearing apart the foundations of society, as implanted tapeworms have turned their human hosts into a seemingly mindless mob.

Sal and her family are trapped between bad and worse, and must find a way to compromise between the two sides of their nature before the battle becomes large enough to destroy humanity, and everything that humanity has built. . . including the chimera.

The broken doors are closing. Can Sal make it home?
"A riveting near-future medical thriller that reads like the genetically-engineered love child of Robin Cook and Michael Crichton." —John Joseph Adams on Parasite
More from Mira Grant:


Begin Reading

Table of Contents

A Preview of Feedback

Orbit Newsletter

Copyright Page

Hachette Book Group supports the right to free expression and the value of copyright. The purpose of copyright is to encourage writers and artists to produce the creative works that enrich our culture.

The scanning, uploading, and distribution of this book without permission is a theft of the author's intellectual property. If you would like permission to use material from the book (other than for review purposes), please contact Thank you for your support of the author's rights.


If you ask the questions, best be sure you want to know.


This isn't what I wanted. Please believe me.
This isn't what I wanted at all.


December 18, 2027: Time stamp 08:04.

[The recording quality is low, filled with static and choppy artifacts left over from the transcription process. Portions of the file have either not been uploaded or have been overwritten by some error in the codec. The lab in the picture is clearly mobile, clearly in a state of constant flux: Every piece of equipment is on a rolling stand of some sort. Some machines are supported by hospital gurneys. People rush by in the background, making no effort to turn away or conceal their faces. By this point in the outbreak, there is no longer any reason for them to fear having their identities revealed.]

MALE VOICE: We're recording.

[A woman in a wheelchair rolls into the center of the shot. She is blonde and abnormally pale, as if she has not seen the sun in some time. Dark circles surround her blue eyes, speaking of sleepless nights and long hours spent poring over data. She wears no makeup. Her hair has not been styled. A small whiteboard rests in her lap, covered in a string of apparently random letters and numbers. She holds it carefully, keeping the whole thing visible to the camera.]

DR. CALE: My name is Dr. Shanti Cale. If you are seeing this, you know who I am. I am either your creator or I am the cause of your empire's final dissolution. Either way, I am sorry. I did what I did because I thought I was making the world better. Maybe, in the long run, history will decide that I was in the right. But right here, right now, it's difficult to see that as anything other than a pretty dream in a world that isn't very forgiving of such things.

[Dr. Cale looks down at the whiteboard, and then back up at the camera. She smiles. It's a sad expression, tangled with old ghosts and unforgiving realities.]

DR. CALE: At the end of this introduction, the video feed will switch to a compressed data format. The data encryption code that I am currently showing you will allow you to extract and analyze this week's findings. Unencrypted, I will say this: The specimens recovered from the San Francisco, Sacramento, and Oakland reservoirs have all shown genetic similarities to the worm originally encoded for chimera Subject nine-A, code name "Persephone." Because of Persephone's unique ability to bond with her host without causing severe neurological damage, I recommend you stick to bottled water for the foreseeable future. All of you, I mean. I haven't been able to fully analyze these new worms. They may pose a danger to preexisting chimera whose integration was accomplished through less natural methods.

[Her smile twists, turning almost vicious.]

DR. CALE: Hear that, Sherman? You may have just fucked yourself. Putting her into the water supply probably seemed like a brilliant idea. It may have paid the wanted dividends initially, but you may well have created a bigger problem for us all down the line. You may have doomed the very people you were trying to protect. I know how that feels. Like mother, like son.

[Her smile fades entirely.]

DR. CALE: My next message is for Colonel Alfred Mitchell, of the United States Army Medical Research Institute of Infectious Diseases, or whoever may have taken his place. I know you are attempting to track and monitor my people. We are taking precautions to remain off your radar. You will not find us. You will not recover us. But you have someone of mine. You know who I am referring to. We are prepared to offer you a trade. Proof of life, and proof that she has not been harmed, and I will provide encrypted copies of my research on the modified D. symbogenesis organism. Return her to us, intact, and I will provide unencrypted copies of my research.

[Dr. Cale is calm, almost serene, despite her obvious physical exhaustion.]

DR. CALE: I have been accused of being a traitor to the human race because I refused to take sides when my children began turning against their creators. Me, who made them, not Dr. Steven Banks, who altered them recklessly and without concern for what his changes might mean. Not Dr. Richard Jablonsky, who died knowing what he had unleashed, without contacting the authorities or sharing his knowledge with the world. Me. Just me, alone. Well, fine. If you want me to be a traitor to the human race, then I will be. I will gather my children close, and I will see them through this storm. Return my daughter to me, and I will help you fight the chimera who think more of themselves than they do of humanity. Keep her, and I'll let you burn.

[Her smile returns, terrible and thin as the blade of a razor.]

DR. CALE: My name is Dr. Shanti Cale. I am the traitor you have ordered me to be, and I am a better monster than you deserve. The broken doors are open. You will never make it home.

[The picture goes briefly to a negative image, static chewing at the edges of the screen. Then it is completely gone, replaced by a several-megabyte flood of data. This onslaught of encoded information continues for ninety seconds before the visual feed abruptly terminates. The audio continues for a few seconds more, then ends.]

[End report.]

December 3, 2027: Time stamp 23:57.

This is not the point of no return.

The point of no return is a philosophical construct, an idea that looks beautiful on paper or in a computer model, but which cannot hold up under the bearing strain of reality. The point of no return is reached in a thousand places at the same time, a thousand little fractal iterations all coming together and collapsing until the center cannot hold. It's chaos theory given flesh, and it can't be stopped.

I wasn't there when the center failed to hold, but I understand why it meant as much as it did. This is not the point of no return. But it is the only point that matters.

Claudia Anderson was dying.

The people who had custody of her body didn't know her name, and wouldn't have cared if they'd been told. They didn't know that she'd been top of her class at Berkeley, that she'd been a competitive chess player since she was eleven years old, or that she had liked to attend comic book conventions wearing costumes that she had made herself in the privacy of her rent-controlled condo's spare room. None of that mattered anymore. In a way, none of it had really mattered since she signed her NDAs and employment forms in SymboGen's HR office, starting her life down the path that would inevitably place her here, lying motionless, attached to as many machines as they could jam into her veins, slipping farther and farther away.

The people who worked to save her didn't know her name, because it wasn't hers anymore: Claudia Anderson was dying, but in a very real way Claudia Anderson was already dead. They worked tirelessly to save a girl named "Anna," a girl who looked at the world with eyes that were both new and old, innocent and educated beyond her brief weeks in the body she had tried to claim as her own. Anna had shoved Claudia to the edges of her own mind, and then she had shoved more, until everything that had been Claudia had toppled off the cliff into nothingness. All that remained was her body, an empty shell that had become a haunted house in the hands of its new owner.

Claudia Anderson was dead and alive at the same time, falling ever farther, falling too far to make it home.

She had no hospital to sustain her, no gleaming modern facility where miracles could be performed and the course of nature could be reversed. Her bed was a narrow cot being wheeled through endless halls, with a medical team that worked to save her even as they worked to save themselves. She could never have been their first priority, and if she had still been capable of anything as complicated as gratitude, she would have been grateful. Death had been held in abeyance for too long. It was time to go.

Inside Claudia Anderson's skull, a war was being waged.

Rather than recognizing the D. symbogenesis tapeworm as an ally, the body was responding to it as what it actually was: an invader, an intruder designed to disrupt the natural course of things. Immune responses were mustered, and Claudia's temperature had been spiking steadily for hours as her body sought to repel the invasion. Unable to understand what was happening, the implant—Anna—reacted by burrowing deeper into the tissues around her, damaging them irreparably in the process. It was a chain reaction too far gone to be stopped, no matter how hard the attending medical professionals worked.

Maybe if they had been able to stop running. Maybe if they had had access to a better hospital. The world was built on a scaffold of "maybe," and it was crumbling down around their ears, leaving them standing on ground that had never been capable of supporting their weight.

"Dr. Cale, we're losing her."

"I need an epi!"

"I'm not getting a response."

"We can't find a pulse."

"Call it."

The time of death was shortly after midnight on December 4, 2027. Claudia Anderson would not be mourned.

Neither would Anna.


Destroy your files before you leave your office. Deletion is not sufficient. Destroy the computer. Shred and burn the paper records. Leave nothing behind. It's over.


Is there a point when all this will start being fair?


We are receiving reports of infection in individuals who had been previously confirmed free of the SymboGen implants (see attached personnel screening report), and have already completed a full course of preventative antiparasitics. As our doctors have tested these drugs, and found them fully effective against D. symbogenesis in both egg and cyst form, we must assume that the worms are finding their way into our people through some other mechanism. I do not know what this mechanism may be. My troops do not know what this mechanism may be.

We need help. We need support. We need more bodies on the ground. We are on the verge of losing the San Francisco Bay Area. If this is a location you are prepared to surrender to the enemy, pull us out. If it's not, give us the support that we need and deserve, as representatives of both your armed forces and your medical community.

Don't just leave us here to die.


I let her go.

On some level, I must have known what she was planning to do. She's always been conflicted. Human or parasite; good little girl or independent adult woman; Sal or Sally. I walked with her right into the physical representation of that conflict, and when it offered her the chance to save everyone by giving up herself, I expected her not to take it. I thought she'd be…

I don't know whether I thought she'd be stronger, or whether I thought she'd be weaker. I don't really know anything anymore, except that she's gone, and I have no idea how we're going to get her back.

God, Sal, I'm sorry.


Chapter 1


They kept me inside an unused office for an hour while Colonel Mitchell and Dr. Banks went over what had happened at Dr. Cale's lab. Three soldiers with USAMRIID patches on their shoulders stood over me, guns in their hands and eyes narrowed with justified suspicion. I looked calmly back at them, trying to pretend that my hands weren't cuffed behind my back, that my boyfriend and my allies and my dog weren't being escorted across San Francisco by soldiers who had no reason to let them live. Colonel Mitchell was never going to let me go. If his people wanted to shoot my friends in the head and leave them among the sleepwalkers and the deceased, what was going to stop them? Not me. And certainly not the ghost of Sally Mitchell.

It was starting to occur to me that I would never know if he broke his word and killed them all. I had nothing left to bargain with.

One of the men made eye contact with me. It may have been an accident, but it still happened. I seized the moment, offering him a small, strained smile. I've always looked young for my age—Sally left me with an excellent bone structure to call my own, and when people searched my eyes for experience, they didn't usually find it, since technically I'm only about eight years old. Hopefully he would read my smile as shy, the sort of thing he might receive from any human prisoner under the same conditions.

He paled, and turned his face away when he realized I was looking at him. I let my smile die. These men either already knew who—and what—I really was or they knew me as their superior officer's daughter, and hence dangerous in a whole different way. I was a mission objective to them, nothing more and nothing less. As long as they brought me back alive, they would win.

Keeping my face neutral, I looked around the office for what must have been the hundredth time. It was small, corporate, and virtually pristine. The only personal touches were a Disneyland snow globe on one corner of the desk and a picture frame next to the computer. The frame faced away from me; if it held anything other than the blank paper from the frame store, I would never know. I felt a strong, irrational urge to ask them to turn that picture around, to let me see, but I didn't say anything. It was going to be one more unsolved little mystery in a world that was full of them, and had been since the day I made my "miraculous recovery" in the hospital, coming back to life after the doctors had already pronounced me dead.

Only I wasn't the one who'd been pronounced dead. I wasn't the one who'd suffered a massive seizure while driving and steered my car into a bus. I wasn't the one who'd concealed important facts about my own medical history in order to protect my father, whose military career depended upon him not being revealed as a secret epileptic. All those things had been done to and by Sally Mitchell, the human girl whose body I now called my own. I had earned it. I was the one who put her brain back together, however instinctually, creating something that I could use to sustain the body she had left behind. I was the one who had to clean up her messes. Including this one.

My name is Sal. I was born in a lab in the basement of the SymboGen building, where geneticists who thought they were being clever combined a little bit of this, a little bit of that, and a whole lot of terrible idea to make a tailored "biological implant" for Sally Mitchell, one that would naturally secrete the antiseizure medication she needed kept off the books and outside of the public eye. I was placed in her body when I was still an egg smaller than the head of a pin, hatching in the hot warm dark of her digestive tract and growing to maturity there. I hadn't known what I was or where I came from, because those were concepts that didn't matter to a tapeworm—and all pretty language and marketing nonsense aside, that's what I was. A tapeworm, a member of the genetically engineered species Diphyllobothrium symbogenesis, designed to improve and promote human health, human well-being, human welfare.

What my creators didn't bank on was the fact that all living things will seek to improve their own circumstances, and for me—for all the worms like me—that meant taking control of our own lives. I had been migrating through Sally's body at the time of the accident, which is how I was able to survive the gross physical damage to her abdomen that had crushed at least part of my own long, threadlike body. While she was hooked to life-support systems and her parents were exploring other options, I was working my way through the bones at the back of her skull, following an instinct I didn't understand until I was able to connect myself to her brain. Normally, that was where things would have gone wrong. Very few worms, even ones as carefully designed as I was, can fully integrate with their human hosts. But I was made to prevent seizures, and I integrated with minimal physiological issues. For all intents and purposes, I became Sally Mitchell the first time that I ordered her body to open its eyes.

For literally years, that's what I believed I was. I thought I was a human girl suffering from traumatic amnesia, and not a tapeworm wearing a human body like a fancy dress. I let Sally's parents and Sally's doctors and Sally's therapists try to make me into someone I had never been and had no real interest in being. Nothing any of them had to tell me about her made her seem like an appealing person to transform myself into, but still, I tried. I tried for their sakes, and because they said they loved me, and I believed them. How could I have done any different?

They were my family. They were all I had. That's what I'd thought for a long, long time, and now that I was finally starting to understand what they'd really been to me—what they had done to me, all in the name of trying to bring Sally back—I was right back in their hands.

Or at least, I was right back in the hands of Sally's father, Colonel Mitchell, and since he was the only member of the Mitchell family who had ever given signs of understanding what was going on with me, that didn't make me feel any better. His wife, Sally's mother, hadn't known, I was sure of that, and I was almost as sure that his other daughter, Joyce, hadn't known either. She would have told her mother. She would have told me. Instead, she had told me how much nicer I'd become since my accident, and how happy she was that we were finally friends, instead of just people who happened to be related.

No. Joyce couldn't have known. But Colonel Mitchell had known from the beginning that I wasn't his daughter. He had looked into the eyes of an alien creature, of a chimera born from the union of tapeworm and human, and he had decided that the appropriate thing to do was try to brainwash it into becoming human after all. Brainwash me into becoming human after all.

And now I was his, to do with as he pleased. That had been the cost of saving Nathan, Fishy, and Beverly… and as I remembered the looks on their faces when I turned away from them, I realized I wasn't sorry. I had lived the first six years of my life going along the path of least resistance and letting other people make my decisions for me. I'd been allowing my tapeworm nature to dictate my decisions. I was a tailored symbiont; I existed to be led. But I was here because I had stood up and said I would go if my friends could be set free… and that was an impulse from the human side of me, wasn't it? That was me struggling to become a person who acts, a person who controls her own fate.

I needed to be that person now. Because the person I had always been wasn't going to cut it anymore.

The men who had been assigned to watch me snapped to attention as the office door swung open. Colonel Mitchell stood framed in the doorway, holding his hands folded behind his back.

"Who opened the door?" I blurted, before I could think better of it.

Colonel Mitchell blinked at me. "That's your first question? Not 'What happens next' or 'Where are we going' or 'Did your friends make it back to their transport,' but 'Who opened the door'?"

"You could lie to me if I asked you any of those questions, but the big thing right now is yes, who opened the door? You can't have moved your hands that fast. You'd have to be a wizard, and there's no such thing as wizards."

"That's not what you said when you were a little girl," he said, stepping into the room. Another soldier stepped in right behind him, answering my original question. Colonel Mitchell ignored him. All his attention was on me, even though it didn't feel like he was looking at me at all. He was seeing Sally. Poor, dead, long-buried Sally.

"You checked the mailbox for your Hogwarts letter every day for an entire year," he continued. He walked toward me as he spoke, one hand dipping into his pocket. "You were so sure that your owl was coming, and you told me over and over about how you were going to be the greatest witch of your generation. Do you remember which House you hoped to be Sorted into?"

"I don't know what you're talking about," I said. I was supposed to be keeping up the pretense of being Sally Mitchell, somehow returned from the grave and reclaiming ownership of her own body. That didn't mean that I could somehow recall family trivia and jokes that she had shared with her father long before I arrived on the scene. "We always lived in the same house."

If Colonel Mitchell was disappointed by my answer, he didn't show it. "I'll see about finding you copies of the Harry Potter books," he said, moving behind me and taking hold of my wrists. I stiffened, but he was just undoing my handcuffs. They hadn't been tight enough to hurt. There was still a feeling of glorious freedom as they fell away. "I know you've had trouble with dyslexia since your accident, but they're available in audiobook form. You can listen to them, and then we can talk again."

I bit my lip to keep myself from laughing. The world was crumbling outside the building where we stood. People were dying by the thousands, maybe by the millions; cities were being deserted, and the two sides of my heritage—the humans and the tapeworms—were destroying each other at an unspeakable pace. The human tendency to focus on the inconsequential to avoid focusing on the traumas at hand could be completely ridiculous at times. It was a habit I'd picked up from the humans who'd raised me, but that didn't mean I really understood it.

The slow, constant beating of the drums in my ears reminded me to stay on guard, no matter how amused I was. They were my compass through a world that seemed determined to destroy me, and they weren't going to allow me to relax. Not one bit.

"Okay," I said, keeping my voice meek and low. He seemed to be in good spirits; whatever Dr. Banks had said to him, it hadn't been enough to make him lose his temper. I decided to risk another question. "Did my friends make it back to their transport okay?"

He paused before walking in front of me, a solemn expression on his face and my newly removed handcuffs dangling from one hand. He held them up like they were a reminder that I needed to stay mindful of my position and the limitations it entailed. "I have no idea whether your friends made it back to their starting point, and to be honest, I don't care. A group of my people escorted them into the streets, and maintained visual contact until they were approximately one mile from this location. Then my people came back here. The goals of this mission were to retrieve you and to harvest certain essential data from Dr. Cale's research before she moved again. Both these things have been accomplished."

I frowned. "How did you get that data? We didn't give Dr. Banks anything. Dr. Cale had him under guard from the time he stepped into the building. She even took his hard drive away, and we're sure he didn't have any tracers or trackers, or—"

Colonel Mitchell was looking at me oddly. The soldiers who shared the room with us weren't looking at me at all. I stopped talking. I was showing too much interest in the people I had allowed to leave me behind. That sort of thing would indicate that I wasn't as committed to being his daughter as I was claiming to be.

"I just, I talked to him, but I was still pretending, you know?" I made my eyes as big as I could, trying to sell the part. "To be Sal, and to think that they were on my side, not on the side of the parasites. So I know how thoroughly they searched him."

"They didn't search him for wireless sniffers, or for download signals," said Colonel Mitchell. "If they had, they might have found out how much of their data he was copying. But that's none of your concern. I'm glad to see that you can still care about people, even if you're caring about the wrong ones. No matter. That will change soon enough. Gentlemen, prepare her for transport." Then he turned, and walked back toward the door.

He took the handcuffs with him, which meant I could put my hands up to ward the soldiers away when they started closing on me. Their faces were grim masks, efficient and cold. "No, please," I said, not knowing what they were about to do, but knowing that whatever it was, I wasn't going to enjoy it—not when they were looking at me like that.

I was so focused on the ones in front of me that I never saw the one who slipped behind me with the Taser. Electricity arced through my body, stunning and scrambling everything, and then I hit the floor, and if the pain continued, I didn't know about it anymore.

Everything was warm and dark and perfect. The drums hammered ceaselessly away in the background, and I felt like I was floating on a hot tide of weightlessness and peace. Everything would be perfect forever if the world could just stay exactly the way it was, filled with comforting darkness and the sound of drums.

Only no. Everything wasn't


  • "A riveting near-future medical thriller that reads like the genetically-engineered love child of Robin Cook and Michael Crichton."—John Joseph Adam on Parasite
  • "Readers with strong stomachs will welcome this unusual take on the future."—Kirkus Reviews on Parasite
  • "Fans of [the Newsflesh] series will definitely want to check this new book out. But fans of Michael Crichton-style technothrillers will be equally enthralled: as wild as Grant's premise is, the novel is firmly anchored in real-world science and technology."—Booklist on Parasite
  • "Grant extends the zombie theme of her Newsflesh trilogy to incorporate thoughtful reflections on biomedical issues that are both ominously challenging and eerily plausible. Sally is a complex, compassionate character, well suited to this exploration of trust, uncertainty, and the price of progress."—Publishers Weekly on Parasite
  • "It's a well-grounded medical wariness that gets at the heart of the what the Parasitology series will be asking: What happens when the cure is worse than the disease?"—NPR Books on Parasite
  • "An exceptionally creepy medical-horror thriller that's the perfect spine-tingling read for Halloween...[a] roller coaster ride."—RT Book Reviews on Parasite (4 1/2 stars)
  • "Deft cultural touches, intriguing science, and amped-up action will delight Grant's numerous fans."—Publishers Weekly on Deadline
  • "The zombie novel Robert A. Heinlein might have written."—Sci-Fi Magazine on Feed
  • "A masterpiece of suspense."—Publishers Weekly on Feed (Starred Review)

On Sale
Nov 24, 2015
Hachette Audio

Mira Grant

About the Author

Mira Grant lives in California, sleeps with a machete under her bed, and highly suggests you do the same. Mira Grant is the pseudonym of Seanan McGuire — winner of the 2010 John W. Campbell Award for best new writer. Find out more about the author at or follow her on twitter @seananmcguire.

Learn more about this author