Principal Cookson informs Helen that her position has become untenable - a student tragically died because Helen crossed a line. Helen worries that Sam has been taken against his will, but O'Brien struggles to trust her story due to her previous unreliability. Cressida lures Sam further into her dark web, exposing self-harm scars, while Helen and Tessa frantically search Cressida's dorm room for clues about Sam's whereabouts. In a final desperate bid to save her son, Helen races into the Peak District. However, Cressida has shadowed Sam in her darkness, making it a fight for Helen to bring him back