But, for now, let’s leave behind such historical mysteries and move forward to the present . . .

  CONGO OF TODAY

  After back-to-back brutal wars—the First and Second Congo Wars (from 1996 to 2003)—the DRC remains in a precarious state. Corruption runs rampant, placing the country at number 168 out of 198 on the “corruption perception index” index, as prepared by Transparency International. And though the country is one of the richest in natural resources, it still remains one of the poorest. Rebels, militias, and warlords plague large sections of the country. Poachers wreak havoc. But there remain many heroes who fight for the DRC’s future, including members of the Institut Congolais pour la Conservation de la Nature (ICCN). These eco-guards—like Ndaye—struggle daily, in blood and strife, to protect those natural resources against far worse than just poachers. In a country teetering on the cusp, other nations—most notably of late, the Chinese—have sought to steal its riches, heralding a new era of colonialism that threatens to be just as brutal and devastating as those reported during William Sheppard’s time. So, if this bit of fiction shines a brighter light on what’s happening under the Congo’s dark canopy, all the better.

  On a side note, the tragic events of Lake Nyos in Cameroon described in this book—where 1,800 people were suffocated by a methane burst from that lake—truly happened back in 1986. Likewise, that same risk hangs over the heavily populated Lake Kivu, which straddles the border between the Democratic Republic of the Congo and Rwanda. There, millions would be killed if that lake ever exploded, which is a distinct possibility in the earthquake-prone region.

  A BIT ABOUT BEASTS AND BATS

  First, forgive a veterinarian-turned-author from indulging in his own creature creation. Certainly, many of the insects and animals featured in this story are of my own imagination. Still, I sought not to craft them in an entirely fanciful manner, but to borrow and steal from other species, while also adhering to basic behavior and biology. Though, even some of that behavior and biology may seem fantastical. Like ants who have empathy (they do!), or orange-tinted dwarf crocodiles who are evolving in real time while trapped underground (they are!). I also enjoyed shining a light on the monogamous nature of jackals, the temperament of hippos, and the existence of aardwolves.

  I also devoted a large chunk of the book to bats and their strange biology, especially in regard to their unique ability to harbor viruses. I thought it might be of special interest during the time of COVID. All of the details concerning bats and viruses found in this book are true. Like how viruses are deeply entwined into a bat’s unique immune system, how viruses tie into their ability to fly, how they contribute to the species’ amazing longevity, even how viral DNA is baked into their genetics—and ours.

  So, let’s take a closer look at viruses in general. I’ve broken this next section into (hopefully) digestible parts.

  ORIGIN OF VIRUSES

  This novel discussed many of the current theories about the origins of viruses. Like if viruses can truly be considered living or are they simply self-replicating machines. That same debate dovetails into which came first—a sort of chicken and the egg scenario. Did viruses devolve from some other larger cell? Or did they come first and jump-start life on this planet—what’s known as the Virus World Theory. I’ll let virologists hash that out. Though, I lean toward the latter. Why? Simply because so many of our most important genes—from embryo development to immune function—come from viruses. Even the Arc gene, gained from viruses, is the foundation for our big brains. Without viruses, none of us would be around.

  SEARCH FOR VIRUSES

  Frank’s job, as described in this book, is vitally important. Yes, he helped saved Kane, but that’s not what I mean. Seventy-five percent of all emerging diseases in the past century—Ebola, HIV, COVID-19—were passed to the human population from animals, known as zoonotic transmission. The Smithsonian’s Global Health Program is just one organization that strives to search for the next pathogen that might trigger another pandemic. They employ many board-certified veterinarians and other specialists to collect data, to gather specimens from the field, all to create a database of potential threats.

  What frightens many of the virologists I spoke to—especially after COVID—is what they dub “Disease X.” This is a theoretical disease pathogen capable of spreading rapidly, an organism that modern science has no preventative or cure against. How close was COVID to being that frightening Disease X? Let me just say that researching this novel during the time of COVID was not good for one’s nerves. We mostly escaped what could have been far worse. Still, we need as many Franks out there as possible, so we’re better prepared next time. And trust me, there will be a next time.

  GIANT VIRUSES

  The first of these jumbo viruses was isolated from an amoeba in 1992. Due to its size, everyone thought it was a bacterium at first. It wasn’t until 2003 that it was reclassified as a virus. Since then, many other giants have been discovered. That doesn’t mean we understand them—not in the least. These viruses contain thousands of genes, most of them remain unknown. Like the Pandoravirus. Ninety percent of its 2,500 genes don’t resemble anything else found on earth. Then there’s the Yaravirus, an organism where all of its genes are alien. Such viruses are also strangely stubborn, even capable of coming back from the dead. One giant—Mollivirus sibericum—was discovered frozen in the Siberian permafrost. It was revived after 30,000 years of frozen hibernation. So, if we’re searching for a Disease X, maybe we’d better pay particular attention to those giants.

  OMNIVIRUS

  Again, forgive a veterinarian who spent too much time talking to virologists during a pandemic. Of course, I had to create my own Frankenvirus. The idea, though, came from before COVID. I had read about one giant virus’s ability to protect itself by employing a CRISPR-like technique of gene editing. I also leaned on my own veterinary background and understanding of Toxoplasma gondii, how that protozoan alters the behavior of not only rodents, but also us. I was also intrigued by how a virus can trigger different manifestations, like how rabies can present in both a “furious” state or a “paralytic” form—which might sound familiar after reading this book. Likewise, with mad cow disease. It’s caused by a nasty prion that triggers aggressive behavior in cows, but in humans, it presents with depression and loss of coordination. I also learned that one of the theories for the origins of prions is viruses themselves. Those bits of self-replicating chains of protein might indeed have been cast off from a virus.

  So, I took all of these details to create the Omnivirus featured in this book. But considering everything above, maybe it truly is out there, waiting for Mother Nature to be fed up with us two-legged upstarts.

  And speaking of Mother Nature . . .

  MOTHER NATURE—GREEN IN LEAF AND RED IN THORNS

  I had read the first book listed below (The Hidden Life of Trees) back when it first came out in 2016. I was fascinated by the revelations concerning the interconnectivity of a forest, and not just the trees, but also the underlying fungal network that joins it all together. I knew I always wanted to raise this topic in a novel—and this was my chance. I had tackled something similar in my older novel Amazonia, but with all the new research, I wanted to expand it even further. If you’d like to learn more about this intriguing and eye-opening topic, please check out these titles:

  Hidden Life of Trees: What They Feel, How They Communicate—Discoveries from a Secret World, by Peter Wohlleben

  Brilliant Green: The Surprising History and Science of Plant Intelligence, by Stefano Mancuso and Alessandra Viola

  Finding the Mother Tree: Discovering the Wisdom of the Forest, by Suzanne Simard

  Likewise, I’ve always been fascinated by the biology and evolutionary history of fungi and mushrooms, especially their role in the transition of life from sea to land. The oldest fungus was indeed found among fossils discovered in the Congo, dating back 810 million years. That organism is believed to have helped build the Earth’s primordial soil, where the first plants would eventually take root. As to the oldest living fungus, that’s indeed the honey mushroom (Armillaria ostoyae). It can be found many places, but the oldest is the patch in the Malheur National Forest of eastern Oregon. It’s estimated to be 8,000 years old, covering 3.5 square miles, and weighing 35,000 tons—making it also the largest living organism.

  Though the claim of being the oldest has a major competitor in the “Trembling Giant”—or Pando—of Utah. That stand of 40,000 interconnected clones of quaking aspen (Populus tremuloides) weighs 6,600 tons and may be as old as 80,000 years (though some believe it could be over a million years old).

  Yet, no matter who wins that award, it’s still a reminder that we humans are very young, and in our youth, often very ill-mannered when it comes to the stewardship of this planet.

  GADGETS AND GIZMOS

  This book is chock-full of all sorts of destructive weaponry—and one resilient Russian-made vehicle. The Shatun ATV 4X4 is worth looking up. I encourage you to watch videos online of its tough and nimble nature. I want one—just in case I’m ever trekking through a jungle (or a swamp, or a tough par 3 on a golf course).

  As to weapons, the MOAB is a real bunker-busting bomb. The Massive Ordnance Air Blast, better known as the Mother of All Bombs, is indeed as strong as a small tactical nuclear weapon. The robotic dogs featured in this book—the Quad-legged Unmanned Ground Vehicles—are real. Though, I’ll stick to the furry versions myself.

  In regard to firearms, Gray’s KelTec P50 handgun is real. But Kowalski’s razor-disk-spitting Shuriken is of my own invention—though a prototype for something similar was put into production several years ago. Similarly, Kane’s wireless bandolier that allowed Tucker to remotely drop small charges (flash-bangs, smoke bombs, and grenades) was my own creation. Because why should Tucker have all the fun?

  And speaking of Kane . . .

  MILITARY WORKING DOGS AND THEIR HANDLERS

  I love Tucker and Kane. But how did this dynamic duo come to life? I first encountered this heroic pairing of soldier and war dog while on a USO tour to Iraq and Kuwait in the winter of 2010. Seeing these pairs’ capabilities and recognizing their unique bonds, I wanted to try to capture and honor those relationships. To accomplish that, I spoke to veterinarians in the U.S. Veterinary Corps, interviewed handlers, met their dogs, and saw how these duos grew together to become a single fighting unit. I also vetted their stories with former and current handlers to be as accurate as possible. If you’d like to know more about war dogs and their handlers, I highly recommend two books by the author Maria Goodavage:

  Soldier Dogs: The Untold Story of America’s Canine Heroes

  Top Dog: The Story of Marine Hero Lucca

  Now, I expect to get a fair amount of hate mail following what happened to Kane. Why was I so cruel? I’ve featured Tucker and Kane’s exploits through four novels, a novella, and a short story. After so long, I felt it disrespectful not to be as realistic as possible about the hardships endured by these brave four-legged soldiers. Though Kane’s fate may wound many readers, I wanted to honor the sacrifice of military working dogs everywhere, those who have lost life and limb in service. Of course, this is not the last you’ll see of Tucker and Kane. In fact, I need a new name for Kane’s feral protégé. If you have any ideas, go to my website, send an email, and share your suggestions. There might even be a reward.

  Okay, that’s it. You may have noted a conspicuous absence from this novel, one former assassin-turned-ally. Fear not, Seichan will be returning from Hong Kong. Though she was sidelined in this book, she is about to be challenged like never before—as someone returns with a vengeance and has Sigma in their sights. So, rest up, gird those loins, and be ready for an adventure that changes everything—and I mean, everything.

  Acknowledgments

  Laurie Anderson, one of my favorite musicians, wrote a song titled “Language Is a Virus.” If she is correct, then any book must be a vector for transmission. For this novel, the language contained herein was made all the more potent via a group of first readers who helped me engineer and polish this story to its most infectious form: Chris Crowe, Lee Garrett, Matt Bishop, Matt Orr, Leonard Little, Judy Prey, Caroline Williams, Sadie Davenport, Sally Ann Barnes, Denny Grayson, and Lisa Goldkuhl. And a special thanks to Steve Prey for the Congo regional map. But I also have to single out David Sylvian for all his hard work and dedication in the digital sphere. And Cherei McCarter, who has shared with me a bevy of intriguing concepts and curiosities, several of which are found in these pages. And a special acknowledgment to moukies for his most helpful read regarding the authenticity on subject matters raised in this novel. Of course, none of this would happen without an astounding team of industry professionals who I defy anyone to surpass. To everyone at William Morrow, thank you for always having my back, especially Liate Stehlik, Heidi Richter, Kaitlin Harri, Josh Marwell, Richard Aquan, Caitlin Garing, Andrea Molitor, and Ryan Shepherd. Last, of course, a special acknowledgment to the people instrumental to all levels of production: my esteemed editor, Lyssa Keusch, and her industrious colleague Mireya Chiriboga; and for all their hard work, my agents, Russ Galen and Danny Baror (along with his daughter Heather Baror). And as always, I must stress that any and all errors of fact or detail in this book, of which hopefully there are not too many, fall squarely on my own shoulders.

  About the Author

  JAMES ROLLINS is the #1 New York Times bestselling author of international thrillers that have been translated into more than forty languages. His Sigma series has been lauded as one of the “top crowd pleasers” (New York Times) and one of the “hottest summer reads” (People magazine). In each novel, acclaimed for its originality, Rollins unveils unseen worlds, scientific breakthroughs, and historical secrets—and he does it all at breakneck speed and with stunning insight. He lives in the Sierra Nevada.

  Discover great authors, exclusive offers, and more at hc.com.

  Also by James Rollins

  Unrestricted Access

  The Last Odyssey

  Crucible

  The Demon Crown

  The Seventh Plague

  The Bone Labyrinth

  The 6th Extinction

  The Eye of God

  Bloodline

  The Devil Colony

  Altar of Eden

  The Doomsday Key

  The Last Oracle

  The Judas Strain

  Black Order

  Map of Bones

  Sandstorm

  Ice Hunt

  Amazonia

  Deep Fathom

  Excavation

  Subterranean

  BY JAMES ROLLINS AND REBECCA CANTRELL

  Blood Gospel

  Innocent Blood

  Blood Infernal

  BY JAMES ROLLINS AND GRANT BLACKWOOD

  The Kill Switch

  War Hawk

  Rights and Attributions for the Artwork in This Novel

  Congo Map

  Drawn by Steve Prey. All rights reserved. Used by permission of Steve Prey

  Ant

  Purchased with Enhanced License from Shutterstock

  Royalty-free stock photo ID: 1777308743 by merearts

  (image edited by author)

  https://www.shutterstock.com/image-illustration/illustration-black-silhouette-ant-isolated-white-1777308743

  Vines

  Purchased with Enhanced License from Shutterstock

  Royalty-free stock photo ID: 547120837 by Thoom

  (image edited by author)

  https://www.shutterstock.com/image-vector/cross-thorns-black-white-simple-vector-547120837

  Okapi

  Drawn by author

  Message

  Drawn by author

  Prester John Map

  Public domain (image edited by author)

  1710 Map

  Public domain—from the Historic Maps Collection, Princeton University Library (image edited by author)

  Virus Group

  Obtained from a Creative Commons CCO 1.0 Universal Public Domain Dedication (image edited by author)

  Individual Virus

  Obtained from a Creative Commons CCO 1.0 Universal Public Domain Dedication (image edited by author)

  Mycelium

  Purchased with Enhanced License from Shutterstock

  Royalty-free stock photo ID: 353791034 by Zita

  (image edited by author)

  https://www.shutterstock.com/image-vector/round-mildew-mycelium-vector-illustration-353791034

  Virus Raft

  Public domain (image edited by author)

  Spiked Virus

  Licensed under the Creative Commons Attribution-Share Alike 4.0 International license

  (https://creativecommons.org/licenses/by-sa/4.0/deed.en)

  Source: Sarah Duponchel and Matthias G. Fischer from [https:// journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1007592]

  (image edited by author)

  Okapi 2

  Drawn by author

  Cross

  Drawn by author

  Jungle Church

  Purchased with Enhanced License from Shutterstock

  Royalty-free stock photo ID: 1776268763 by Klauss Egon

  (image edited by author)

  https://www.shutterstock.com/image-photo/old-church-on-middle-jungle-1776268763

  Genome Map

  Purchased with Enhanced License from Shutterstock

  Royalty-free stock photo ID: 1288865194 by Tartila

  (image edited by author)

  https://www.shutterstock.com/image-vector/genomic-analysis-visualization-dna-genomes-sequencing-1288865194

  Cross 2

  Drawn by author

  Gravestone

  Drawn by author