When Ray's Uncle Brian appears to be suffering from depression, Arthur seeks the advice of Percy Vallins, a successful businessman but known manic depressive, who suggests that Brian is shamming. And indeed he is, as a means of keeping Ray's interfering mother out of his florists' business. Having 'cured' Brian, Arthur then has to call in Detective Sergeant Rogerson when ex-cop Henry Keys, another manic depressive, to whom Arthur has sold a car, locks himself in the Winchester club toilet.