Charming, widowed Berlin 'senator' (city state minister) Hans-Werner 'H.W.' Glehdorn finds raising orphaned teens Michael and Jennifer and little Toby hard to combine with his mandate, which includes attributing major public works and other contracts. The workaholic is inclined to let sister in law Claudia Weigoldt assume a maternal role, but the kids push their aunt away. As their late mother's testament grants them a home boat on river Müritz, the trio sneaks off the next holiday period to inspect their heirloom retreat, forcing H.W. to dodge work and follow. Long before him arrived runway socialite bride Isabell, daughter of leading Berlin contractor Harry Kolditz whom the city is awarding a major contract, who seeks quiet under a false name. Hans-Werner duly mistrusts her intrusion, but as he must return to Berlin, the kids insist he hires Isabell to mind them aboard, as none of the Glehdorns has a clue how to handle it, only she.