Feature-length episode. The team is baffled by the conflicting possible motives after two women are shot dead in a house basement - and the investigation isn't helped by Jack having to work alongside an old flame, the ambitious DI Chrissy Reed. Meanwhile, Leo faces a difficult choice when he is asked to prove his pathologist mentor made a mistake in a case that resulted in a mother being imprisoned for smothering her baby to death. Emilia Fox, William Gaminara and David Caves star