Buy a jar of pickled rollmop herring, or go to the fishmonger and ask for some fish heads, say they’re for your cat.

revenge using rotten fishOpen up your victim’s desktop computer casing and place one or two rolls / headsĀ  inside, screw the casing back together. The smell is insidious and truly vile, but if you don’t know where to look, the office stink takes ages to trace.

Alternatively drop the rollmop somewhere inaccessible in the home, behind very heavy furniture, under the washing machine, dropped down the cavity behind the central heating boiler, or even within the recesses of the victim’s sofa. Anywhere will do!