Ostensibly, "Pearly Gates" (Peter Sellers) is a French couturier selling posh frocks, but we know in reality he's a crook. Imagine his chagrin when his latest crime falls foul of the police! Imagine how much worse it gets when he discovers that it wasn't the police at all, but a gang who "IPO" (Impersonate Police Officers). That's below the belt! Meantime, the rather supercilious police inspector "Parker" (Lionel Jeffries) starts to get embroiled in this too as his bosses don't much like the idea that there are fake officers out there robbing with impunity. The most unlikely of truces now ensues as both have to bury the hatchet and concoct a plan to entrap their rather shrewd, and well briefed, protagonists. The enormous sum of £500,000 is to be used as bait but what's the betting the plan goes pear-shaped? There's a good dynamic between Sellers and Jeffries here with a well paced and engagingly daft story unravelling over a quickly paced ninety minutes. Some familiar faces make up the supporting cast and the denouement - well I quite liked that! The humour is simple and uncomplicated, relying on some characterful performances and some spirited efforts on screen, and I did quite enjoy this.