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.

Five years earlier Dean Scott was found dead of shot-gun wounds and suicide was the verdict. Now ex-hooker Alice Hill tells the team she was at Dean's house at the time and believes he was murdered. Mike Barnes, Dean's shifty partner, rooked his widow Pam and turns out to be an ex-bank robber, who used the loot to start the business. The search switches to the other robbers, one of whom has gone straight and the other - who fought with Dean the night before the death because he was seeing Pam - is under witness protection. The missing loot is found but the fact that Pam and Alice already knew each other complicates the murder theory.