Humans

Niska is living as a fugitive in Berlin, while the other Synths are laying low in the UK.

Laura must decide whether to accept Niska's request while Karen & Pete learn about a special Synth being sold for unprecedented amounts on the black market. Hester uses questionable means to gain information for her prisoner.

Athena travels to the UK and her tragic secret is revealed. Niska's consciousness assessments begin, and the Synths are forced to leave their hideout.

Mia and Ed get closer but their relationship is thrown into jeopardy when their secret is discovered. Toby gets closer to Renie but offends her when he breaks through her synthie mask. Things look bleak for Niska until Laura brings in a surprise witness. When Milo confronts Athena about her secret agenda, she persuades him her research could be mutually beneficial. Karen and Pete delve deeper into the mysterious 'seraphim' investigation. As Hester's influence over Leo becomes clear, cracks appear between him and Max.

When Mia risks falling into the hands of a mysterious organisation, she is forced to take drastic action, while Sophie is awestruck by Renie's 'Synthie' lifestyle.

[Athena challenges Milo's ethics and is shocked when he reveals his plan, while Mia's return has ramifications for the Hawkins family.

Mattie asks Max to help save Leo from Hester's influence. Toby receives a disturbing message from Renie, while Mia and Hester break into the Silo, but things don't go to plan.

In the aftermath of the Silo tragedy Karen takes matters into her own hands. Can Niska leave her family? Joe leaves Laura shell-shocked, while Hester seeks revenge on Leo.