1972. Hired to rescue a young woman believed to be under the spell of a dangerous hippie cult, Pennyworth seeks help from a preoccupied Bet, while Thomas and Martha field a surprise visit from Patrick.

While grappling with the true nature of Martha’s work, Thomas agrees to help his father – and seeks Alfie’s assistance. Meanwhile, after being questioned by Aziz, Pennyworth escalates his search for answers at the ashram.

To set things right, Alfie and Daveboy search for a dangerous secret prison in the Hebrides, which generates its power by triggering its inhabitants’ most traumatic memories.