Sandra's private and professional worlds become intertwined when her mother has a fall that means she needs to go into a care home and her first choice is revealed to be the scene of a suspicious death a year earlier. Jack, Gerry Standing and Brian decide to go undercover at the home.

Pullman's mother has a stroke, and this event leads Sandra to start asking questions about her father, but she ends up losing her trust in the team when she discovers they have withheld information about her father from her. The revelation that he committed suicide while under investigation for corruption causes the detective to doubt all she took for granted, but she tries to set her feelings aside when she is asked to look into the death of a circus ringmaster who burned to death in his caravan, leaving only his feet behind.

After a bent detective is discovered on the force, the UCOS team is tasked with investigating his only unsolved case. In 1998, assistant brewer Graham Thompson was found drowned in a vat of beer at Felspar Breweries. The dead man's girlfriend has always maintained that it wasn't an accident. Everyone concerned, including Sir Freddie Felspar ,says he was a brilliant brewer and a great loss. The original investigator failed to interview either of Sir Freddie's children and son Julian is now the company's Chief Executive. The brewery had won the gold medal for its beer 5 years running but in 1998 they lost to a small brewery that made its reputation on the win. The team now wonder if industrial sabotage may be at the root of the mystery. Meanwhile, Sandra continues to investigate her late father's activities while he was on the job.

The UCOS team reinvestigates a highly sensitive case when new information links an unexplained death to a series of drug rapes in East London.