Season 1, Episode 13 Alienville

Molly discovers that the entire population of a small Virginia town has been infected with the alien virus and that a leading astrophysicist is among them. Molly visits the town and learns the aliens are involved in a secret project that could lead to massive exposure of the virus. Back at the lab, the Threshold team prepares for an infected woman to give birth, but they don't know if the baby will be alien or human.