With the Sun Hill arsonist still on the loose, Sam Nixon is determined to crack the case and briefs the team on the latest attack on the Hendersons’ house.

After learning Cheryl Wilkes was spotted at the scene of the inferno, Sam and Phil question her at work, where she reveals she was at the house to see her boyfriend Jay. Meanwhile, Reg and Tony find an empty vodka bottle by the side of the house wreck.

Later, Sam and Phil are called to Cheryl’s work where she tells them Jay accused her of starting the fire before punching her.

Phil arrests Jay for assault, but back at the station, Jay insists Cheryl started the fire and claims she is a compulsive liar. And when Tony and Reg view CCTV footage showing Cheryl buying vodka, and find her fingerprints all over the empty vodka bottle, it seems the case is clear cut. Cheryl even admits to starting the blaze, but after further investigation, Phil and Sam aren’t so sure.

Elsewhere, Sergeant Smithy and PC Lewis Hardy find Robert Crawley smashing up Eddie Marsh’s market stall, claiming he’s been sold a dodgy computer game. It’s not the last they see of the Crawley family – later they respond to a shout from Robert’s pregnant wife Belinda, who’s been assaulted on the street.

Also, Sam tells ex-lovers Phil and Stuart that she will be the new DI.