‘Extant’ Season 2, Episode 4: ‘Cracking the Code’
Molly tries creating a virus to destroy alien hybrids and discovers that aliens are trying to communicate with humans through a hidden message in their DNA. Elsewhere, Lucy helps Ethan run away from Charlie to help him recover memories of Molly.
An astronaut (Halle Berry) returns home from a yearlong solo mission in space. She tries to reconnect with her husband and son in their everyday life. Her experiences in space and home lead to events that ultimately will change the course of human history.
Extant season 2, episode 4 airs July 22 at 10 p.m. EDT on CBS.