 Shaw agreed to take certain roles only on the condition that he have complete freedom to rewrite his dialogue . When he appeared in It Happened Here , a 1966 World War II film , he wrote many of his own lines , which the filmmakers later said " gave his dialogue an individual slant which enhanced his performance " . He also helped in other aspects of the filmmaking , including casting ; he introduced the filmmakers to Fiona Leland , who would be cast as Shaw 's wife in It Happened Here . He wrote other plays , including The Ship 's Bell , The Cliff Walk , The Glass Maze and Cul de Sac . He also wrote Poems , a collection of his personal poetry , which saw a limited print of 300 editions by publisher Exeter University . 
