Paul Furneret, a young artist working in Paris in 1901, is invited to attend a s ance at Camille Flammarion's observatory after having participated in an experiment in "automatic drawing" at another s ance a week earlier, in which he drew a picture, while unconscious under hypnosis, of a young woman recognized by one of the participants as his dead daughter. Paul's friend, Victor Marvaud, is unable to accompany him, as arranged, because...