Season three of Silo continues the saga of a dystopian society of 10,000 people living underground under mysterious circumstances, while revealing an origin story set centuries earlier. In the present, Juliette Nichols (Ferguson) survives her forced “cleaning” but returns with memory loss as the silo recovers from rebellion and faces a dangerous new threat. Meanwhile, in the “Before Times,” journalist Helen Drew (Jessica Henwick) and Congressman Daniel Keene (Ashley Zukerman) uncover a conspiracy that pulls them into a chain of events with catastrophic, irreversible consequences.