Naïve good-doer Dr. Arnold Arnie Fischer continues his father's Münich medical practice, which he and ruthlessly ambitious buddy-colleague Gregor plan to turn into a state of the art tinnitus center. That requires cannibalizing the neighboring apartment, which Arnie also owns, but senior tenant Zabel bluntly refuses to move out and he hesitates to evict. The way seems clear when Zabel had a fatal heart attack, but his granddaughter, cellist Mathilda Lenz, moves I with pre-teen son Merlin, and Arnie has an instant crash on her, hence plays the friendly neighbor. Meanwhile Gregor hires henchmen to make her life unbearable, and Arnie ex Ines who left the man she dumped him for and shoves of their rebellious daughter Pia (17). Arnie is caught in his lies and torn by conflicting loyalties, but soon forced to make choices.