Mervin is about to fly home but finds himself at the centre of a murder investigation when a body is discovered in his shack. As Mervin professes his innocence, the team can't work out how the victim ended up inside a locked building with no sign of forced entry. The woman's identity remains elusive until they discover she was volunteering at a local turtle conservation charity, and suspicion falls on her colleagues. Meanwhile, Selwyn grapples with his most difficult decision yet when he delivers some personal news to Mervin that turns everything on its head.