This was Will Hay's last film which is a black comedy and it is a fitting tribute to a splendid career. Hay plays William Fitch a disbarred solicitor. The opening sequence of the film sees a role reversal for Hay in that he for once is outwitting others with his mental agility in defending himself against allegations of writing begging letters. He uses all his legal knowledge and the prosecution crumbles and he walks from the court a free man.

He meets his prosecutor Claude Babbington in the pub and buys him a  commiserating drink,.It is while they are there that they come across the inauspicious figure of Arthur Grimshaw who will pester them throughout the rest of the film. Grimshaw is a murderous madman whom Hay unsuccessfully defended in a case of forging fivers, which saw him go to prison for a tenner (years). Grimshaw is now seeking his revenge on all those who collaborated on getting him sent down. He informs our hapless duo that he has formed a list and that he is ready to perform 'six little dramas of retribution, all beautifully staged.' He tells Hay that he is number six on the list and that number one, the Judge as already been dealt with in a drowning 'accident.' Grimshaw takes a morbid delight in informing Hay and Babbington via a way of clues as to who is next victim is going to be, before disappearing.

In a wild attempt to inform the victims before Grimshaw can perform his dirty deeds the duo get themselves into quite a few farcical situations. Alas they are unable to prevent any of the killings and Hay soon finds himself near the top of the infamous list. He gets wind of a plan by way of Grimshaw's clues that he plans to blow up the House of Lords because Hay had tried to take Grimshaw's appeal to them there, but it was thrown out. The film culminates with Hay and Babbington trying to stop Big Ben striking twelve o'clock noon because this is the time set by Grimshaw to set off the explosives.

In a scene very reminiscent of a Harold Lloyd film we see our hapless duo hanging onto Big Ben's clock hands trying to prevent it from striking noon. The police arrive after crowds gather to watch and they arrest Grimshaw, but Hay and Babbington are left hanging there, congratulating themselves on a job well done but wondering how they are going to get down from this precarious position.