It's not necessarily much of a problem when the man of the house gets on better with his pet than his wife. That's the case with Erich and his constantly carping wife Waltraud. But Erich's discovery of a fish as a soul-mate is a tragedy. This particular fish is, in fact, a carp, and it's being kept in the bathtub waiting to be served to Erich's mother as a special birthday dinner - a fine kettle of fish. Not only is what little domestic bliss Erich has at stake; his inheritance depends on it as well. So he's faced with a real dilemma. Halfway between the bathtub and the kitchen the unthinkable happens. A small, seemingly innocuous white tablet suddenly has an unforeseeable effect, and it sets off a tumultuous chain reaction.