Benito Cereno is a novella with a very strange form. It begins with narration from the point of view of Captain Delano, an American out at sea who comes upon the stranded ship of Captain Benito Cereno. Cereno tells him that the ship has been struck by disease and the bad luck of calm seas, but something strange is going on.
The mystery of the plot is offset by the abrupt switches in point of view, from a first person narration of the events to an official record of the events. Despite this, it's definitely worth reading.