Hancock dreams of becoming the great detective 'Sexton Hancock' and proceeds to unravel a complicated murder plot.

Hancock, a junior clerk in a City office for 19 years, receives a promotion when his army friends, who met at a reunion, place large orders with the firm. However, they are all fraudulent orders and Sid has the takings!

Hancock meets a girl at an upper class party. He believes that she has money and Sid tells her that Hancock has money, so a marriage is rapidly arranged. But all is not as it seems!

Hancock and Sid decide to earn some extra cash by signing on as babysitters. The pleasant evening is spoiled when they start arguing over the TV and the baby starts crying. But who are those two extra visitors?