Story : Suspicions are running high after the discovery of Cal's body. Cal's friends - Rob, James, Tina, Janine and Annie - are questioned by the police about what happened on the night of the murder. In an attempt to raise spirits, Rob plans a surprise for James's birthday, but he is not in the mood to celebrate and seems intent on uncovering a secret. What relevance does this secret have to Cal's death? Meanwhile, Ruth is charged with finding out who supplied the friends with ketamine - a mission that takes her to the heart of the case.