Hercule Poirot after his last cases has needed to take a break, but the situation will force him to return. On the eve of All Affairs Day, a mystery has happened in post-war Venice. Detective Poirot will have to leave his retirement much to his regret, he already imagined himself in Serenissima living quietly without any strong emotion. Arriving in Venice he will begin to investigate a murder case surrounded by a city prepared for the festivities.