Carla and Prentice Hayes are found murdered in a violent knife attack. Jamie Hayes is missing, initially leading the team to speculate that he could be responsible. But Jimmy is convinced that Jamie could not have mutilated his mother in this way. Aware of her altercation with Prentice the previous evening, Perez pays a visit to Olivia Lennox. She's in her room, shaken, with blood on her clothes. Could she be responsible or an innocent bystander?

Having heard of the traumatic events in Glasgow, an angry Duncan confronts Jimmy over his fears for Cassie's safety. Although shaken, Cassie seems pleased that Perez has trusted her with the truth. Now sure that Zezi is still being held on the island, Perez and Sandy pay Morag Dunwoody a visit in an attempt to extract further information. However, matters take a more dramatic turn when Morag's house is petrol-bombed.