Mia (Gemma Chan) and Ed (Sam Palladio) get closer but their relationship is thrown into jeopardy when their secret is discovered. Toby (Theo Stevenson) gets closer to Renie (Letitia Wright) but offends her when he breaks through her synthie mask. Things look bleak for Niska (Emily Berrington) until Laura (Katherine Parkinson) brings in a surprise witness. When Milo (Marshall Allman) confronts Athena (Carrie-Anne Moss) about her secret agenda, she persuades him her research could be mutually beneficial. Karen (Ruth Bradley) and Pete (Neil Maskell) delve deeper into the mysterious ‘seraphim’ investigation. As Hester’s (Sonya Cassidy) influence over Leo (Colin Morgan) becomes clear, cracks appear between him and Max (Ivanno Jeremiah).