Poirot receives an order to investigate the case of the substitution of the most valuable diamond. Therefore, he goes to a wonderful island in the middle of the Adriatic, where an exquisite audience gathers. The sky is clear, the sea is transparent, champagne - from the ice.
But Hercule Poirot is not happy: he sees evil everywhere under the sun. And now - the murder. The great detective has nine suspects. Everybody has a motive. And each has an iron alibi. Even Poirot is puzzled.