No other account of the writing contest verifies this bizarre project as Mary Shelley
outlines it. Polidori himself, in the introduction to his realistic novel Ernestus
Berchtold; or, the Modern Oedipus 1819), identified that work as the one he began
as the response to the challenge given by Lord Byron. He did, however, also produce
a horror-story of his own in direct competition with Byron's unfinished fragment,
which he published in 1819 as The Vampyre; a Tale.