The Affair at the Victory Ball by Agatha Christie

Following a lavish costume party, one guest is found dead in what appears to be a drug overdose—but Poirot suspects a more theatrical murder. As he analyzes costumes, motives, and old resentments, he unravels a plot driven by revenge and performance. The plot dances between appearances and truth, wrapped in high-society drama. A cleverly staged mystery with a dramatic final act. Poirot proves once again that no detail is too small—or too sparkly.