 Colonel Hall is keen to set a new Army record for inducting new recruits into the army. He aims to enlist 309 men in less than 2 hours and ALMOST achieves this by inducting 308 men + 1 chimpanzee. Somehow Zippy the chimp has been enlisted as Private Harry Speakup and once the Pentagon have him on their books the only way to get him out of the army is by convening a Court Martial. Bilko s head is also on the block and so he decides to act as Private Speakup s legal counsel to ensure a fair trial and save his own skin.