After pulling off a small train robbery, 'Little Walter' and his gang are forced to hide out on a remote Cornwall island in an abandoned monastery, disguised as monks. With them comes 'Bikini' (Barbara Windsor), Walter's girlfriend, who is given the job of cook to the group, despite never having cooked in her life. After a few initial setbacks, they slowly adjust to their new contemplative life of tending animals and crops, surviving the added tribulations of visits by a group of tourists and two of the real monks who had been forced to sell the monastery after falling on hard times, including Brother Lucius (Corin Redgrave).