The activities of a sleeper cell from another world operating in modern-day Los Angeles. The agents arrive emotionless, follow orders without question, and none of them knows the true nature of their mission on Earth. What a few of them do know, however, is that something unexpected has happened: Our emotions affect them like a dangerous, uncontrollable virus. Once indulged, any feelings they have toward us can suddenly shatter their carefully codified order.
Cain Johnson is the cell's vigilant, determined Enforcer, tasked with investigating agents who "go rogue." A new arrival, he struggles to understand the strange human ways. When cell agent Adam Bridges betrays his own kind because of his love for Donna Shaw—an ordinary human woman—Cain is ordered to hunt him down. Ezekial Smits is the cell's Assimilator, orients new arrivals to this world, then monitors their progress and reports anyone he deems "unstable." The ambitious Tara Spader is in charge of media disinformation; she'll follow any order the silkily domineering Sector Chief Uriah Selleck gives, as long as it assures her advancement within the cell. Naomi Tyler Moore is Tara's counterpart and total opposite, as seductive as she is free-spirited, using her powerful sexuality to gather information on unsuspecting human males.