Hugo Brinkmeyer is a rather obsessive tax accountant, with not much of a personality outside his work. His long-suffering wife Gerda sometimes finds him difficult, and they have no children. Leaving a club together one night, he takes the wrong hat with him. Eventually tracing the owner, so as to get his own back, the other man (Schwidders) asks his advice about his own tax affairs; he reveals that he has twin sons by an extra-marital affair, and his wife doesn`t know. Can he nonetheless get tax relief for them? He takes Schwidders` papers with him agreeing to see what can be done, and goes on to a birthday party of an old school friend, Süsskind. It`s in another club, and he stays longer than he should, and drinks more than he should. Late at night the club owner asks him for help with the accounts, and Brinkmeyer agrees, and stays even later going through the books, and drinking, with help from a dancer, Rita.