'The Secret of Marrowbone') is a 2017 English-language Spanish psychological horror mystery drama film written and directed by Sergio G. Sánchez, and starring George MacKay, Anya Taylor-Joy, Charlie Heaton, Mia Goth, and Matthew Stagg.

The film tells the story of the titular Marrowbone siblings (MacKay, Heaton, Goth, and Stagg), who relocate from England to their mother's ancestral estate in Maine, where they are faced by a sinister presence at home.

Marrowbone was screened in the Special Presentations section at the 2017 Toronto International Film Festival and released in Spain on 27 October 2017 by Universal Pictures.

In 1968, Rose Fairbairn brings her four children; Jack, Jane, Billy, and Sam, from England to her childhood home, the Marrowbone Residence, in rural Maine.

Before dying, Rose makes Jack promise that he and his siblings stay together and hide the news of her death until he can become their legal guardian.

She reads it, which reveals that Simon found the house six months ago, and Jack locked his siblings inside the attic to keep them safe.

He tries to give Simon back the money box, who leads Jack to the secluded place but is thrown from a cliff and knocked out by his vengeful father.

Meanwhile, Tom arrives at the house and finds a bricked attic entrance, convinced the money is hidden there, and tears down the wall, but he is attacked by Simon.

[2][3] In July 2016, Anya Taylor-Joy, Mia Goth, George MacKay and Charlie Heaton joined the cast of the film.

The website's critical consensus reads, "Marrowbone's effective setting and strong cast can't make up for thinly conceived characters and a story short on genuine scares.