An Englishman's home may well be his castle, but it would be a very different castle indeed if Germany had won WWII. Set in an alternate 1970s on an Earth where Germany won the Second World War and is now occupying England, Peter Ingram (Kenneth More) is the lead writer of a popular soap opera set in Blitz-era London. Ingram's life sees little adventure. He knowingly turns a blind eye to the realities of local Nazi rule, opting for the easy life. After the inclusion of a Jewish character in his television series is met with strong objection, his eyes finally begin to open. And when the woman he loves (Isla Blair) reveals that she was born a Jew, he has a difficult decision to make. Will Peter join his lover in the Underground resistance or continue to lodge his head firmly in the sand?