A Head Full of Ghosts

A Head Full of Ghosts is a horror novel by the American author Paul Tremblay, published in 2015. It tells the story of a New England family whose fourteen-year-old daughter begins to show symptoms that the doctors cannot stop or explain, and it is narrated years later by the younger sister who watched it happen. Veronika Franz and Severin Fiala wrote and directed a film adaptation.

The Barretts are an ordinary suburban family until Marjorie starts to show symptoms of acute schizophrenia. The doctors cannot stop her outbursts, and the household becomes a house of horrors as her condition worsens. Out of options, the parents turn to a local Catholic priest, who suggests an exorcism and believes the teenager is the victim of demonic possession.

Father Wanderly also brings in a television production company, which proposes to film the family's crisis as a reality series. The novel therefore has three layers: Merry's account of the events, the family's blog about the possession and the televised version. The reader has to decide which account to trust, and the book deliberately leaves the question of possession open.

Merry is an unreliable narrator who says as much. It is a standalone book.