Mary makes a horrifying discovery, sending Annie on a dangerous collision course with Frances. Meanwhile, Ben attempts to reconcile with Mary, and Des becomes attached to a difficult patient.
Mary promises Des that she'll never put the hospice at risk again. Mary and Frances meet an elderly cancer patient. Jess realizes that something's wrong with Naomi.
Ben asks the police to look into Frances, forcing Mary and Des to put their assisted deaths on hold with devastating consequences. Meanwhile, Des and Lucy's relationship is brought to a head, and Naomi's downward spiral continues.
All seems well for Mary, Ben has forgiven her, and she and Des have decided to move forward with the death retreat. The only nagging concern for Mary: her daughter Jess hates her and doesn't believe a word out of her mouth.