In 2006, when a zookeeper's body was discovered in the tiger enclosure, the death was ruled a tragic accident. New evidence now suggests it was murder. As the team tracks down clues, animal rights activist Brian clashes with the zoo's PR department.

A man found murdered in an alleyway seven years earlier is identified on a website about unsolved cries. The team reinvestigates the case, but the man seems to have no past. Meanwhile, job cuts are imminent, and Brian and Gerry fear being downsized

When a frightened young woman offers new information about the killin of the leader of a biker gang, the team agrees to take another look at the case--and perhaps prevent a second murder. A former colleague tells Sandra that she is wasting her career.

In 2004, a prominent physics professor disappeared from a train bound for Paaris. When his wife receives emails from someone claiming to know the reason, the team reopens the case. Then their boss, DAS Strickland, is warned off by a shadowy Whitehall figure.

Reinvestigating the murder of a respected antiques dealer reunites Sandra with an old flame, DCI James Larson. Will she follow her head or her heart? Meanwhile, Brian faces his own crisis at home. His wife, Esther is behaving very oddly. Is she having an affair?

A psycologist arrives to conduct a study of older men in the workplace and asks the team for help on a personal matter, Years earlier, her berother, a bicycle messenger, was the victim of a hit and run that left him with severe memory loss. Now he claims he was a target--and still is.

New information sheds light on the 2009 death of a popular market trader. It seems that she was drugged and killed by a serial rapist, but with that case still ongoing, the team must look elsdwhere for clues. It doesn't help when Sandra's mother comes for a visit.

When DNA tests on a charred remains from 1996 reveal family ties to a fingerprint analyst at the Home Office, drawing the team into a world of immigration loopholes and Albanian gangs. Meanwhile, Gerry takes a class in French cooking and meets a saucy woman

When DNA tests on a suspected robber prove his innocence, they also point to an earlie r crime: the 15 year old murder of an unarmed vagrant on a tube train.The trailleads the team to the victim's posh relatives, and Brian has a run-in with the homeless community.

The team reinvestigates a decades old death at the Natural History Museun. Did senior palentologist Bernard Fletcher die from a fall, or was he murdered? To solve the case, the aging detectives must walk amoung the dinosaurs.