A huge discovery by our young fans is interrupted when they are thrust into the dangerous world of Jessica Hyde. Meanwhile, two doctors with very different career trajectories are both pulled into the path of a deadly flu.

Jessica continues to hunt for answers while our underdogs must make a crucial decision. Michael is done being pushed around.

A clue in Utopia leads Jessica and the crew to a mysterious new ally. Thomas plots a unique way to handle Michael, while Christie makes a decision.

Inside the St. Louis Hotzone, Michael must make a life-or-death choice. As things grow increasingly dangerous, Jessica comes face to face with someone from her past.

Jessica must reckon with a shocking revelation as Arby questions his own past. Michael unravels as he searches for answers.

Arby finds a new purpose while Becky makes a decision that tears the group apart. Michael is about to have the worst day of his life.

In the season finale, as the world eagerly awaits Christie's vaccine, Jessica and the group must race to stop the Undoing.