British reporters suspect an international cover-up of a global disaster in progress... and they're right. Hysterical panic has engulfed the world after the United States and the Soviet Union simultaneously detonate nuclear devices and have caused the orbit of the Earth to alter, sending it hurtling towards the sun.
The Duchy of Grand Fenwick decides that the only way to get out of their economic woes is to declare war on the United States, lose and accept foreign aid. They send an invasion force (in chain mail, armed with bows and arrows) to New York and they arrive during a nuclear drill that has cleared the streets.
Naive Stanley Windrush returns from the war, his mind set on a successful career in business. Much to his own dismay, he soon finds he has to start from the bottom and work his way up, and also that the management as well as the trade union use him as a tool in their fight for power.
