Mr Brittas Changes Trains - S4.E4

Brittas is to attend an important dinner meeting but Helen, knowing it will be a disaster that she too will need to attend, develops lockjaw. After a staff visit to a hypnosis show, certain staff members show erratic behaviour (Colin tells people he loves them whenever he hears the word 'need'; Linda barks instead of speaking). When the hypnotist arrives to solve the problem, Brittas is accidentally hypnotised, making him a much better person - until its effects wear off at midnight.