Paula Dennstein and Therese Schwarz want to get off to a flying start with their newly opened law firm. Unfortunately, their first joint case does not promise a fee. Single parent Willi Schulz, whose wife died in a traffic accident, cannot afford legal counsel. The desperate family man is in big financial troubles: he has to pay a whopping 20,000 euros cancellation fee for building a house that never materialized. The lawyers work "pro bono" for him and his two children - each in their own way. During her research, the well-connected Paula comes across fraudulent practices by the construction company and its agent Tino Matt. The fact that she violates legal rules causes trouble with her extremely correct partner Therese. A conflict also threatens the two of them at another point: Without knowing it, Therese got involved in an affair with her legal opponent in Paula's divorce from Felix Dennstein. The charming but tough Thomas Lange should ensure that Paula gets as little as possible despite legitimate claims.