text: Plot Through her stepsister Claire Clairmont, Mary Godwin and her future husband Percy Shelley come to know Lord Byron. During the summer of 1816, Lord Byron invites them to stay for a while at Villa Diodati in Switzerland. There they meet Byron's physician friend, Dr. John Polidori. On 16 June, while a storm rages outside, the five of them amuse themselves by engaging in a game of hide-and-seek. Later in a parlor, Percy proclaims his fascination with science; Polidori tells him of his interests in sleepwalking and nightmares. Lord Byron shows his guests Phantasmagoria, a book of horror stories he purchased from a shop in Geneva, and the three alternately read excerpts. This inspires them to hold a séance gathered around a human skull, during which Claire has an apparent seizure. Mary describes them as Claire's "horrors," and recalls instances during their childhood when unexplained phenomena would occur during them, such as Claire's bed inexplicably shaking, and doors slamming shut by themselves. Polidori brings Claire upstairs to rest.
  During the night, Mary witnesses a shadowy apparition outside the window she and Claire share. Believing Mary was startled by a slamming barn door outside, Percy goes to shut it. While investigating the barn, he is startled by a grotesque creature. Mary speaks with Lord Byron in the billiard room, confronting him about his intentions with Claire, and reveals to him that Claire is pregnant with his child. He suggests she have an abortion, and the two argue, resulting in a physical confrontation.