二战期间,英国科学家欧内斯特爵士为得到德国重要情报,在一次侦察飞行时被德军击落。为了应付德军审讯,他谎称英军中尉法罗,因而被送往英军战俘营。与他关押在一起的英国军官们对他的身份非常怀疑,认为他是德军派来的奸细,对他采取了种种考验,当得知真相后,军官们想方设法帮助他逃回了英国……A somewhat happy-go-lucky bunch of Brits in a German POW camp find their new acerbic fellow prisoner is a key officer who must be got out at all cost.