The elderly British employees of the Permanent Assurance services Company, a staid London firm which has recently been taken over by the Very Big Corporation of America, rebel against their much younger corporate masters when one of them is firing. Having locked the surviving supervisors in the safe, and forced their boss to walk a makeshift plank out a window, they commandeer their Edwardian architecture office building, which suddenly weighs anchor, uses its scaffolding and tarpaulins as sails, and is turned into a pirate ship. The stone office building starts to move as if it were a ship. Sailing through the City of London, they then proceed to attack The Very Big Corporation of America's skyscraper, using, among other things, wooden filing cabinets which have been transformed into carronades and swords fashioned from the blades of a ceiling fan. On ropes, they swing into the board room and engage the executives of VBCA in hand-to-hand combat, vanquishing them.