When Mattie reveals that the Synths are planning to break into the Silo, Laura is determined to find Niska and ask for her help. Mattie asks Max to help save Leo from Hester's influence. Toby receives a disturbing message from Renie. Karen seeks out Athena's expertise and makes a life-altering decision. Mia and Hester break into the Silo, but things don't go according to plan.
Elenco: Gemma Chan , Colin Morgan , Katherine Parkinson , Tom Goodman-Hill , Lucy Carless , Emily Berrington , Theo Stevenson , Ivanno Jeremiah , Pixie Davies , Will Tudor , Sope Dirisu , William Hurt , Carrie-Anne Moss , Ruth Bradley .