We get first-person testimonies from scientists who were attacked by the escaped Peter Farragut. They describe strange behavior and black goo. They're concerned - and, apparently, three victims escaped, which means Alan, Julia, and Sarah are also concerned. But Hatake may be the most concerned, which is why he orders a base-wide search by security teams wielding stun batons.
You know who doesn't have to search? Dr. Boyle, who, while dissecting a monkey, gets stalked and jumped by one of the missing victims of Peter's attacks. Peter's in a vent, creeping on Julia...it's kind of a mess up in Arctic Biosystems.
And the resident scientists are starting to feel the stress. Sarah, in charge of the isolated patients, has to deal with their fear, their agitation, and their unwillingness to cooperate.
Alan, Aerov and Balleseros begin their search, casing the quarters of one Doctor Tracy. They can't find her, but that's because she's all up in Doreen's business, talking crazy-talk (something about "The white room?") and basically acting like someone infected with a horrible disease. She attacks our resident vet and tries to spit black goo at her, but her delirium allows Boyle to escape.
Meanwhile, Balleseros, Aerov, and Alan capture one of the runners, much to the consternation of some of the other Arctic Biosystems staff, who are beginning to freak out and want evacuation. Alan makes the case that evacuation could lead to the virus spreading like wildfire in the wider world...but it remains to be seen whether his argument has really landed.
And Peter...well, Peter is still out there. He confronts Dr. Jordan when she goes to get some morphine for one of the patients, telling her cryptically, "You're here for a reason." But is he talking about her, or about Walker, whose name he mentions right before leaping up into an air vent like Spider-Man. Balleseros tracks our truant scientist into the air ducts, and finds him, but it's not what you'd call a pleasant meeting, and while Balleseros survives unscathed, Peter remains at large, and dangerous.
So, why hasn't he melted like everyone else? Julia is on the case. She investigates Peter's lab with Hatake and discovers that there were two strains of the virus - Narvik-A, and Narvik-B. Tests on rats reveal that Narvik-B, rather than leading to death, instead creates hyper-aggressive behavior and a seemingly unstoppable urge to spread the disease. Could this be why Peter hasn't died, and is instead seemingly on a mission to spread the his black, gooey love around the base?
It seems like the humans aren't doing any better. One of the detainees grabs Sarah and threatens her with a needle, creating a hostage situation that is only defused when Alan steps in and works his scientific charms, removing his helmet to show his solidarity with the detainees. It works, at least temporarily.
Balleseros has a less subtle method. He intercepts a scientist attempting to leave the base, a scientist who threatens to "tell everyone" what's happening at Arctic Biosystems. Balleseros offers a counter-argument in the form of a knife to the guy's back. This guy's agenda just gets more mysterious all the time.
And he's not the only sneaky one. Sarah's detainees pull a fast one on the young doctor, using a faked emergency to stage an escape. Needless to say, neither Hatake nor Alan is psyched by all this, and they have it out in Hatake's office. Whose scientific manhood is bigger? It seems to be a draw at this point.
And, as the episode winds down, everybody's got crazy stuff going on. Balleseros is burying a body. Sarah is shaking - is she freaked out by the attack, or is more going on? Hatake has a scrapbook of pictures of Julia and, you know, crazy silver eyes that he hides with contact lenses. And Julia gets Pyscho-ed in the shower by Peter, who locks his mouth onto hers and gives her a dose of the black goo. Bad times, all around.