Brian Lane enters rehab to treat his alcoholism, but the rest of the team soon join him.
The UCOS team find themselves reinvestigating the death of a well-known timeshare magnate.
The team finds itself at the centre of a shocking cover-up.
UCOS are forced to re-open the investigation into producer Max Stone's death.
The team reinvestigate the disappearance of two young political activists.
The team exhumes the body of a car crash victim after claims she has been seen alive.
UCOS reinvestigate a high-profile riverboat disaster on the Thames after a new witness comes forward claiming the collision was the result of sabotage, rather than an accident. But the case means putting DAC Strickland's wealthy sailing chums under the investigation spotlight; what better motivation could the team have?
A recent rape is linked to two similar attacks at a chocolate factory 10 years previously, leaving the team no choice but to reopen all three cases. The detectives uncover news of an unhappy workforce, learning of an alleged suicide, and their investigation becomes even more complicated when they discover a severed finger was found in one of the company's snacks. After a visit to the doctor, Gerry decides to quit smoking, and instead of resorting to nicotine patches or gum, he enlists Sandra to help him quit
When graffiti appears around London by an unknown person claiming to have murdered a celebrated street artist, the team reopens the four-year-old case. Originally part of a gang, the victim went solo when he received support from a wealthy art patron, leaving the detectives suspicious of his resentful former crew members. Meanwhile, Brian signs up to Twitter to chart the gritty life of a lawman, much to his colleagues' displeasure.
Brian finds the library card of cold case victim Dr Richard Symes, leading him to reinvestigate the death of the professor, who died after falling from the roof of his college three years previously. Sandra and Gerry interview Symes' widow, who believes principal Jeremy Ventham drove her husband to suicide following a conflict over teaching methods.
When 18-year-old debutante Barbara Linden-Warner disappeared without trace 27 years ago, the assumption at the time was that she had been kidnapped and her father, a wealthy British arms manufacturer, paid a ransom for her return. When new evidence emerges about her last movements, the indication is that she may still be alive.
