BEWARE OF SPOILERS. TROPE NAMES ARE NOT WHITED OUT.
- "Nobody else can do this."
A government official who lays the initial groundwork for Project Noah. Young and arrogant, he accompanies Jonas Lear and his team on the expedition to Bolivia, hoping to use Lear's discoveries to weaponize the Virus. However, he is killed during the expedition and never gets to see the fruits of his work.
- Character Death: During Lear's expedition, Cole is among the casualties.
- Ivy League for Everyone: Cole was, according to Richards, a Harvard graduate.
- Posthumous Character: He's never seen in person, having died before the events of the trilogy begin in earnest.
- Small Role, Big Impact: Cole is one of the first characters to die in the trilogy, and is only mentioned by other characters in private thoughts and e-mail correspondence. However, Cole is the one who started Project Noah and set everything in motion.
- Smug Snake: This is how Richards viewed him: an arrogant young man who certainly didn't consider himself to be in danger, a self-styled chessmaster.
- Slimeball: Again, how Richards saw him due to his Bobby Kennedy mannerisms.
- Well-Intentioned Extremist: He was trying to weaponize the Virus, to ensure American domination over other countries.
- "Everybody's on the side of the angels here."
An experienced military colonel, Sykes is 'officially' in charge of the Project Noah facility in Colorado. He recruits Wolgast and Doyle, believing that the Virus could be the key to ending on-going conflicts the United States is involved in. Over time, he gradually becomes more cynical and disillusioned with his own actions.
- Authority in Name Only: He's supposedly in charge of Project Noah, but Richards operates mostly on his own authority.
- Character Death: He's bitten by Babcock, and Richards proceeds to kill him.
- General Ripper: Implied, then averted. He's just another optimist who sees his dreams and ideas for the Virus steadily become twisted.
- Hidden Depths: He seems to just be another shady military official, but it's revealed that he has little power and is deeply conflicted by the going-ons at the facility in Colorado.
- Mercy Kill: Richards shoots him partly for this, but mostly because he threw up on Richards' shoes. Either way, Richards considers it a mercy and he's probably right.
- Motive Rant: Gives an impressive one to Wolgast when recruiting him.
- Mr. Exposition: Sykes gives the details of Project Noah, and the reasons for it, to Wolgast in an extended monologue.
- Well-Intentioned Extremist: He had genuine reasons for getting involved with Project Noah.
- "This is very touching, but if we don't leave now, I'm going to be shooting a lot more people, and I feel like I've had a very full morning already."
One of the Project Noah overseers, Richards is technically a subordinate to Colonel Sykes. In reality, he's the one in charge. Ruthless and intelligent, he holds an iron grip over the facility and often does the dirty work needed.
- Arch-Enemy: With Babcock. Averted in that they don't get their final battle. Instead, he's ripped in two by Anthony Carter.
- Asshole Victim: Richards was a remorseless killing machine, so nobody mourns him.
- Character Death: Anthony Carter rips him in half during the Virals' escape.
- Deadpan Snarker: Second only to Michael in the first book in terms of snarkiness.
- Dragon-in-Chief: To Sykes, but only on the surface. Sykes runs the Noah Project, but everyone is aware that Richards is the one with the real power.
- Even Evil Has Standards: Very, very, very, very low standards. The extent of which is to briefly hesitate and feel almost-but-not-quite remorse following his murder of nuns.
- Half the Man He Used to Be: Ripped in half by Carter.
- Kick the Son of a Bitch: He has a strong distaste for the sadistic, bullying Paulson. When Carter is brought in and it's clear that Paulson bullied him relentlessly, Richards pulls a gun on him and terrifies the young soldier.
- Mercy Kill: Richards shoots Sykes partly for this, but mostly because he threw up on Richards' shoes. Either way, Richards considers it a mercy and he's probably right.
- Last Stand: Decides to make one when the Virals escape, fully aware he'll be killed.
- Psycho for Hire: Guilder lumps him in with the likes of Masters, considering him to be a maniac.
- Omniglot: He speaks a dozen languages.
- Villainous Valour: When the virals get loose, he doesn't even try to escape. He just wants 'a clean exit, with a good showing at the last.' In other words, he wants to kill as many virals as he can before being taken down.
Dr. Jonas Abbott Lear
- "What strange places our lives can carry us to, what dark passages."
A renowned scientist, he leads an expedition to solve 'the mystery of death itself'. Instead he discovers The Virus and is manipulated into adapting it.
- Character Death: Lear dies of natural causes off-page.
- Despair Event Horizon: After the Viral outbreak, he never recovers from the deep guilt of having unintentionally caused it.
- My God, What Have I Done?: After discovering the Virus in Bolivia and working with it in Colorado, he realizes the impact it will have on the world. It's implied that he knew the Virus would get out eventually and all attempts to prevent it's spread would fail, which was why he infected Amy with a modified version.
- Reluctant Mad Scientist: Lear is the architect of the world's end, but his intentions were far from malicious.
- Sole Surviving Scientist: As the surviving creator of the virus, he had the potential to be one of these, but given how he never experimented on anything again after Year Zero, its downplayed.
- Well-Intentioned Extremist: Lear did want to help people and change the world, but his purposes were twisted by others and the Virus was uncontrollable anyway.
- Woobie, Destroyer of Worlds: By trying to 'solve' death and prevent loss, he creates a virus which ends the world. The guilt of his actions weigh very heavily on him.
Dr. James B. Fortes
A member of Dr Lear's original expedition, he ends up working for Project Noah.
Another 'sweep' in the Colorado facility. He later becomes the much-abused 'familar' for Julio Martinez.
- Character Death: Martinez leaves him to die in the cave.
- Even Evil Has Standards: He was a sex offender, but even he was disgusted by the extent of Jude's un-specified crimes.
- Fate Worse than Death: Being a familar for Martinez is no picnic.
- Never My Fault: He has shades of this, saying that what he did (an unknown sex crime) wasn't nearly as bad as what the other sweeps did.
- Tattooed Crook: Ignacio is usually recognized by the snake tattoo on his neck.
- You Have Outlived Your Usefulness: When Martinez is told of Zero and Guilder's plan for the Homeland, he decides he doesn't need Ignacio anymore. He leaves him to die.
Agents & Soldiers
Agent Bradford J. Wolgast
A recently divorced and highly efficient FBI agent, Wolgast is recruited by Colonel Sykes for Project Noah. He is charged with procuring Death Row criminals as test subjects, but things change when he's instructed to retrieve Amy for the Project.
- Character Death: Wolgast seems to die from radiation poisoning, but shows up almost 100 years later as a Viral only to be killed in the explosion that kills the other Master Virals.
- Friend to All Children: A huge aspect of Wolgast's character is his love of children, and he won't hurt or endanger them.
- HeelFace Turn: He was never really an outright bad guy, but he was doing some very immoral things before running away with Amy.
- Heroic BSoD: After his daughter's death.
- Heroic Sacrifice: Wolgast does a Suicide Attack on the Twelve Master Virals.
- Noble Fugitive: After kidnapping Amy.
- The Men in Black: Initially, he was this. Wolgast and Doyle used their government connections to go about their job, leaving no trace behind them...until they went after Amy.
- The Mourning After: Wolgast is still trapped in depression due to the death of his baby daughter and the subsequent dissolution of his marriage.
- Papa Wolf: For Amy. He would do anything to protect her, and does.
- Punch-Clock Villain: While working for Project Noah. He's fully aware that whatever is happening to the convicts is probably not pretty, but goes with it anyway due to his own apathy and depression.
- Promotion to Parent: He's not related to Amy at all, but ends up being a father to her.
- Red Oni, Blue Oni: Blue to Doyle's Red.
Agent Phillip Doyle
- "Look, I'm not made of stone. You think I don't know how fucked up this is?"
A young FBI agent partnered with Wolgast. He's younger and much more gung-ho than his partner.
- The Casanova: Being young, handsome and charming, Doyle is attractive to lots of women. He doesn't find it difficult to pick up women on the road.
- Character Death: Doyle is killed by the Virals during the escape from the Colorado facility.
- Defiant to the End: When Richards goes to execute him, he shows no fear and even smiles at his would-be killer.
Pvt. Derrick Paulson
One of the soldiers stationed at the Colorado facility, his sanity begins to slowly unravel.
- Asshole Victim: Paulson ultimately kills himself. It's hard to mourn for such a monumental bastard.
- The Bully: He takes sadistic pleasure in tormenting those weaker than him, like Carter and Grey.
- Brilliant, but Lazy: He's very intelligent according to his SAT scores, but Richards considers him lazy.
- Character Death: During the fall of the Colorado facility, Paulson shoots himself in the head.
- Driven to Suicide: He puts a gun to his head and pulls the trigger, but not before killing a few of his fellow soldiers and blowing up the elevator.
- Hannibal Lecture: Due to his Sanity Slippage, he winds up delivering one to a stunned and terrified Grey.
- Jerkass: Paulson is a deeply unpleasant individual. He's a sadistic bully who uses his authority to hurt people, often for no reason at all.
- Kick the Dog: Every one of his appearances is a Kick the Dog, whether it's taunting Carter or scaring the shit out of Grey.
- Sanity Slippage: Along with almost everyone else, his mind is torn apart by the influence of the Virals.
- Sociopathic Soldier: Even before he lost his mind, Paulson was a sadistic jerk who took pleasure in hurting others.