Mrs Wilberforce, a sweet old lady, alone in her house, is pitted against a gang of criminal misfits who will stop at nothing. Posing as amateur musicians, Professor Marcus and his gang plot the perfect heist and put the plan into action. Based on the script of the famous Ealing Comedy, the tension and the laughter builds.In this classic black comedy, will the police find out who has committed the robbery? Does Mrs Wilberforce suspect her visitors? Why do the musicians only play one tune? And when the plot unravelswho is safe?