The Tomb

A wealthy, solitary young dreamer grows fixated as a boy on his family's sealed ancestral tomb, and once he finally gets inside it, starts speaking, dressing, and remembering like someone considerably older and longer dead. A final stormy night brings a vision of the family's burned mansion restored to its old glory, and the fire that takes it a second time — after which the young man's own family has him committed rather than asked what, exactly, he thinks he now is.