The Canterville Ghost

"[...]Washington, "for I have tried it with everything. It must be the ghost." He accordingly rubbed out the stain a second time, but the second morning it appeared again. The third morning also it was there, though the library had been locked up at night by Mr. Otis himself, and the key carried up-stairs. The whole family were now quite interested; Mr. Otis began to suspect that he had been too dogmatic in his denial of the existence of ghosts, Mrs. Otis expressed her intention of joining the Psychical Society, and Washington prepared a long letter to Messrs. Myers and Podmore on the subject of the Permanence of Sanguineous Stains when connected with Crime. That night all doubts about the objective existence of phantasmata[...]".