Professor Noel Fitzpatrick tends to a Newfoundland called Billy, who clocks up thousands of miles travelling back and forth from his home in Aberdeen for treatment on its legs. He also attempts to help Barney, a Yorkshire terrier that has a deformity in its neck that is compressing its spinal cord. For owners Linda and Barry, Noel is their last chance, but the operation involves high-risk surgery with no guarantee of success.