Who says that cats and dogs are enemies? The dog Spass and the cat Nelly live happily under one roof. The harmony lasts until once, enraptured with games, they ruin the apartment. Their owners throw them on the street where great adventures await the animals. An evil animal-trainer wants to use them in the circus, other enemies are on the lookout for them and funny situations follow. But the smart creatures find their way home and find themselves in the arms of their young proprietress.