The Count de Cagliostro, who occupies his spare time in working magic, has invited one of his friends to be present at an exhibition which has for its aim the object of showing how much the sense of sight can be abused and deceived. In the center of three fans he arranges a rose-window, which there appears a young page who is suddenly transformed into a marquis of the time of Louis XV. The count brings a large frame, the marquise arranges herself in it, and it seems to the visitor that she is changed into a nymph. He then approaches it to verify the fact, but he perceives that it is the count in person who is in the middle of the picture. But in order to assure himself that he is not mistaken, he strives to grasp him but the latter disappears mysteriously, and the frame, in the center of which he finds himself, is absolutely empty. What he has seen was only a marvelous illusion.