Mary Shelley wrote of Percy Shelley’s doppelgänger, which he and another woman had encountered just before his death:

. . . talking it over the next morning he told me that he had had many visions lately — he had seen the figure of himself which met him as he walked on the terrace and said to him — “How long do you mean to be content” — No very terrific words & certainly not prophetic of what has occurred. But Shelley had often seen these figures when ill; but the strangest thing is that Mrs. Williams saw him. Now Jane, though a woman of sensibility, has not much imagination & is not in the slightest degree nervous — neither in dreams or otherwise. She was standing one day, the day before I was taken ill, [June 15] at a window that looked on the Terrace with Trelawny — it was day — she saw as she thought Shelley pass by the window, as he often was then, without a coat or jacket — he passed again — now as he passed both times the same way — and as from the side towards which he went each time there was no way to get back except past the window again (except over a wall twenty feet from the ground) she was struck at seeing him pass twice thus & looked out & seeing him no more she cried — “Good God can Shelley have leapt from the wall?…. Where can he be gone?” Shelley, said Trelawny — “No Shelley has past — What do you mean?” Trelawny says that she trembled exceedingly when she heard this & it proved indeed that Shelley had never been on the terrace & was far off at the time she saw him.