Disaster alert for dachshund Hercules! His best friend, cat Mr. Beck, has passed away. His humans offer him no comfort: Caro and Marc are struggling with their daily lives as working parents, Luisa is in the midst of puberty, Henri is vying for the title of "most annoying first grader in the world," and the three-year-old twins Milla and Theo are terrorizing their surroundings. Even Grandma Hedwig is of no help, as she is on the hunt for new love. But then one morning, a bag hangs on the door of Marc's veterinary practice. Inside: a black stray kitten. And shortly thereafter, nothing is as it was...