Reggie Grace is a hapless, clumsy medical student but Collier has given him a good report because he fancies his sister, so when a party of big-wigs come to visit the hospital Grace is charged with showing them round. To cause a diversion Collier feigns illness and collapses. The plan is that he supposedly has glandular fever but Reggie correctly diagnoses a slipped disc and is declared the hero of the hour by the visitors. (thetvdb.com)