The Inspector and Deux-Deux are assigned to apprehend Spider Pierre, a notorious pick pocket. The two head to a disreputable bistro and the Inspector orders Deux-Deux to give him some money to flash around in the hopes of trapping Spider Pierre. Deux-Deux tries to talk the Inspector about the money but the Inspector cuts him off.
The Inspector enters the bistro and orders a drink while openly talking about and showing the money in his wallet. However, his wallet is stolen by Spider Pierre and the bartender, thinking the Inspector is a deadbeat, punches him right out of the building. The Inspector asks Deux-Deux to lend him more money to flash around and doesn't want to hear Deux-Deux's protestations about the money. While the two are synchronizing their watches, Spider Pierre steals the Inspector's watch, wallet, badge, comb, diner's card, fountain pen and mother's picture.
Deux-Deux and the Inspector, in a squad car, pursue Spider Pierre into an alleyway. Spider Pierre stops, pulls out an odd gun and seals an area behind him with a spider web. The squad car bounces off the web and is catapulted backwards hard into one of the legs of the Eiffel Tower.
The Inspector chases Spider Web up a rope attached to a building ledge and follows him across another strung between two buildings. However, Spider Pierre releases one end of the rope before the Inspector can safely cross and the Inspector winds up smacking into the side of building. The Inspector falls to the ground followed by the side he ran into and a huge safe behind the wall falling on him and driving him into the subway tunnel below.
The Inspector sees Spider Pierre run up a brick wall but can not pursue him. Undeterred, the Inspector ties plungers to his feet and starts walking up the brick wall. However, the Inspector encounters an open window in his trek and this is quickly followed by an encounter with the angry female tenant, who beats on the Inspector with a broom repeatedly.
Spider Pierre tries to slip away but Deux-Deux captures him with the aid of a spray of DDT. Spider Pierre is put in prison along with the Inspector, who is jailed for passing the counterfeit money Deux-Deux gave him earlier. The Inspector vows to go straight when he gets out and clobber Deux-Deux.