It’s day four of the murder investigation and the three remaining teams are under increasing pressure to apprehend Charly’s murderer. Each team is following different lines of enquiry and adopting different approaches with their witnesses. Freddie Forrester reveals that land agent Alicia Devere is not as sweet and innocent as she appears. New forensic evidence also seems to cast further suspicion in Alicia’s direction. One of the detective teams are ‘clearing the ground beneath their feet’ – eliminating suspects as they go. They revisit the crime scene to try to unearth further clues and confirm the islanders’ movements on the night of the murder. The final team are still doggedly going after their number one suspect, Hamish Gowdie, convinced he’s murdered Charly in a fit of jealousy after finding out she was having an affair with his wife. With two suspects in custody at HQ, the net begins to tighten. But the detectives cannot let their guard down as one more team is about to be taken off the case.