Inspector Callum Isitt teams up with the police to track down four dogs in London, including two St Bernards that have allegedly been beaten by their owners.

Elderly collie-mix Timmy is found surrounded by his own filth and with a large tumor on his face; Shih-tzu Archie can barely see or hear due to his matted fur; French bulldog puppies Yoda and Mogwai lack confidence.

Elderly crossbreed Ben is riddled with fleas; Jason helps a struggling couple maintain a home for their bichon frise; Cardiologist Chris tries to fix terrier Molly's broken heart.

Anthony is desperate to get an abandoned staffie JD to the vet; Keira aids Ruby, a jack russell with a nasty skin condition; Rescue spaniel Ted is training to be a police dog.

Kate finds a home for Max, an abandoned skinny dog; Dog Ellie is terrified of men due to an abusive owner and needs to rebuild her trust; Sarah has to decide if Ruby and Jade should be taken away from their owners.

Mel rescues Zeus from his abusive owner; three generations of dogs are signed over by their struggling owner; Lee needs to get Ted back on track with his police dog training.