During a train trip, the famous playwright Raimundo Rodríguez de Toledo meets again with Cristina, a young woman with whom he had fallen in love some time ago. But the young woman, who shows clear symptoms of instability, lives being forcibly held in an old mansion inhabited by supposed ghosts that are taking her to the brink of madness. Raimundo, accompanied by the faithful waiter Gregorio, will manage to find out the truth of the whole affair.