Liam Neeson voices a monster who visits a boy coping with his mother's terminal cancer in the trailer for A Monster Calls.

The movie comes from director J.A. Bayona, the helmer of The Orphanage, The Impossible and the upcoming sequel to Jurassic World.

First time screenwriter Patrick Ness writes the script based on his own 2011 novel of the same name. The original story is based on an idea by writer and activist Siobhan Dowd, who was contracted to write the story but died of breast cancer before getting the chance to do so.

Alongside Neeson is Sigourney Weaver as the boy's grandmother, Felicity Jones as the mother and Toby Kebbell as the father. The child actor, Lewis MacDougall, was only previously seen in a supporting role in Pan.

A Monster Calls is due out on Oct. 21 against five other films in wide release. There's Jack Reacher: Never Go Back, Boo!, A Madea Halloween, Keeping Up with the Joneses, Ouija: Origin of Evil and I'm Not Ashamed all opening on the same day.