'Haunted Summer' is set in 1816. Authors Lord Byron (Philip Anglim), Mary Shelley (Alice Krige) and Percy Shelley (Eric Stoltz) get together for some philosophical discussions, but the situation soon deteriorates into mind games, drugs, and sex. It is a fictionalization of the summer that Lord Byron and the Shelleys, together with Lord Byron's ex-lover and his doctor, John William Polidori (Alex Winter), spent in the isolated Villa Diodati by Lake Geneva. It is there they devise a contest to adduce the best horror story to kill the dullness of summer. It is also there that one of the world's most famous books was given life - Mary Shelley's 'Frankenstein'.