For her 64th birthday, Anna Marx has only invited two bottles of red wine. There is no reason to celebrate: her best friend is dead, her detective agency is struggling, she is nearly broke, and on top of that, she has been evicted from her apartment. Then, a voice from the past reaches out: her former colleague Gaby Lehmann asks Anna to investigate the sudden death of her mother in a senior home in Bonn. In the midst of Carnival, Anna moves into her former colleague's villa and eventually infiltrates the senior home. Soon, she uncovers a dark family secret – and more mysterious deaths surrounding the home.