
Dog teams participate in real police operations.

Greater Manchester Police's dog squad faces a demanding time as it deals with a siege involving a man threatening to kill his family.

London's dog squad is back in action as a stabbing brings together two of London's top German Shepherd dog teams: PC Paul Caruana and Merlin and PC Andy Miller and Nelson.

German Shepherd Charlie reaches the mandatory retirement age for police service; during one of his final shifts with PC John Tozer, he tracks and locates a suspect hiding after a robbery attempt.

Veteran Diesel takes on Billy, the new puppy on the block, as they hunt for hidden heroin, but Diesel later causes annoyance for his handler PC Adele Gibson during a crackdown on knives and drugs.