
The network descibes the premise as :
"They might be the friendly new neighbors next door or the office workers carpooling alongside you on the freeway. But they are nothing like us. They 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..."
Main characters in the pilot include:
'Cain Johnson' (James D'Arcy), the cell's determined enforcer, tasked with investigating rogue agents.

'Ezekial Smits' (Reg Rogers), is the cell's 'Assimilator' who orients new arrivals to this world, monitoring their progress and reporting anyone he deems 'unstable'. An officious, volatile taskmaster, Smits is also responsible for naming each new agent as he or she assumes human form, drawing from the King James Bible and TV Guide for inspiration.

'Tara Spader' (Freya Stafford) is in charge of media 'disinformation'.
Jonathan "T3: Rise of the Machines" Mostow directs "Them" for CBS Paramount Network Television and Circle of Confusion.