The white rabbit probe puzzles the science team; D'Branin learns a secret from Agatha's past.

Cast: Eoin Macken, David Ajala, Jodie Turner-Smith, Angus Sampson, Sam Strike, Maya Eshet, Brían F. O'Byrne, Gretchen Mol, Bronte Carmichael, Gwynne McElveen, Phillip Rhys