American GI Ernie Williams, admittedly weak-kneed, has an uncanny resemblance to British Colonel MacKenzie. Williams, also a master of imitation and disguise, is asked to impersonate the Colonel, ostensibly to allow the Colonel to make a secret trip East. What Williams is not told is that the Colonel has recently been a target of assassins. After the Colonel's plane goes down, the plan changes and Williams maintains the disguise to confuse the Nazis about D-Day.
as Pfc. Ernie Williams
as Lady Margaret MacKenzie-Smith
as Colonel Somerset
as Lady Vivian
as Sergeant Bridget Stanhope
as Captain Patterson
as Corporal Joseph Praeger
as Colonel Rock Houston
as Sergeant Colin Twickenham
as General Carleton Brown Wiffingham
as Oberkommandant
as Blankmeister
as Mrs. Somerset
as General Zlinkov
