On Helix, Peter and Julia struggle to survive, while Sarah realizes her rapid response test is flawed and Doreen discovers the origins of the mysterious virus.
Major Sergio Balleseros: There are people in the Army, myself included, who are wondering if this outbreak was an accident. Dr. Doreen Boyle: You think Hatake did this on purpose? Why would he do that?
Dr. Alan Farragut: This secure lab allows us to separate vectors from those who are just infected. Daniel Aerov: Vectors? Dr. Alan Farragut: It's what we're calling the infected who are physically attacking others to spread the disease, like Peter.