During World War II, the young undergraduate Stanley Windrush (Ian Carmichael), is conscripted into the British Army. Unlike his friend Egan (Peter Jones (actor)), Windrush is a most reluctant soldier and struggles through basic training at Gravestone Barracks (Hackney spent the first year of his National Service at Invicta Park Barracks). Failing his officer selection board, he is posted to a holding unit, under the command of Major Hitchcock (Terry-Thomas). Most of the soldiers there are malingerers and drop-outs.