In the first case for new recruit Adam, the murder of a swimming instructor leads the team to suspect her ex-boyfriend, a former cop. Meanwhile, Jack has an unexpected visitor.

Nikki, Jack and Adam are brought in to investigate the murder of a surgeon in a hospital. DNA evidence suggests the impossible when it implicates a patient who was under the anaesthetic at the time of the killing. Meanwhile Adam's friendship with the hospital director brings his impartiality into question.