Trainer Graeme Hall tries to solve more dog behavioural problems, visiting a family in East Sussex struggling with rescue puppy Diego, a Rottweiler/Rhodesian ridgeback cross. In Cambridgeshire, cocker spaniel Doug's relentless thievery is destroying any chance of a peaceful retirement for owners Julie and Mark, while Graeme's third stop is in Derby, where he meets two miniature schnauzers known locally as the Krays.