When it turns out that "Twist" (Will Hay) is no good as an headmaster he is turfed out and looking for a new job! An administrative mix up sees him appointed the governor a prison, and after another which sees him temporarily behind the bars, he tries to ingratiate himself with the prisoners and, predictably, they run rings round him as he is soon well out of his depth. Will Hay had good comedy timing and together with a decent cast of regulars manages to raise a laugh or two, but the film is way too long and the joke doesn't really sustain it for ninety minutes. That said, though, it is still quite watchable, if only to remind us was made us laugh in the simpler, less cynical days before the second world war.