When a headless and hand-less body is found in a North London scrapyard, the team led by Sunny are called to investigate.

Cassie and Sunny continue to investigate Fogerty's driving offence.

Cassie and Sunny interview each of the four suspects, who deny knowing the victim. Boulting discovers Walsh was cautioned three weeks before his death, while Collier locates the rest of Walsh's body.

Cassie and Sunny discover Walsh was chased by all four suspects on the night in question. Willets realizes Fiona's blood sample may have been deliberately lost by Liz. The pathologist identifies Walsh was murdered.

Cassie and Sunny interview two of the suspects again and get closer to the truth of what happened to Walsh. Balcombe believes she may have found the cause of death.

Despite a shocking event, the Bishop Street team start to piece together which of the four was responsible for the murder of Matthew Walsh but it is pathologist Leanne Balcombe who provides the crucial piece of evidence.