Based on the bestselling book by Patrick Ness and stemming from an original idea by Siobhan Dowd before that, A Monster Calls centres around Conor O'Malley (Lewis MacDougall), a 13-year-old boy struggling to come to terms with his mother's terminal illness and deteriorating health. School isn't much of a welcome respite for him either as his gloomy outlook and home situation has led the resident bullies there to see him as an easy target.

As life gets more and more unbearable, Conor finds comfort in helping his mother (Felicity Jones) out anyway he can, from getting himself breakfast and putting the laundry on in the mornings to keeping out of the way and immersing himself in his art while she tries to get some rest. But Conor's angst often causes him to stay up past midnight – 12.07am to be precise – as he hopes to evade a harrowing and recurring nightmare which embodies the idea of his mother slipping away.

Before long, Conor finds himself being visited each and every night by a huge, humanoid yew tree (Liam Neeson) which threatens – yes, threatens – to tell him three stories over the course of the next few nights and by the end of the trio, Conor will be required to tell the monstrous tree his "truth" in a fourth story. Reluctant at first, Conor's desperation for distraction leads him to agree to the monster's terms and hence he learns a little something about courage, faith and the complexity of humans.

A Monster Calls (8/10)
A Monster Calls
Felicity Jones might not be in the movie all that much, but the scenes she's in are so warm and touching, you'll find yourself connecting with her character intensely Focus Features / YouTube

Often is the case when a novel is adapted to the silver screen that the characters and story in the film that follow possess a depth and richness that is unusual in our blockbuster-heavy Hollywood these days. A Monster Calls is no exception, however, interestingly in its case, the plot is a glaringly simple one, secondary to the emotional and metaphorical journey that all of the characters and particularly protagonist Conor embark on.

Having made an impressive cinematic debut in Pan, MacDougall is nothing short of remarkable as a young boy with the weight of the world on his small shoulders. While the character has to bear burdens that no child should have to face, MacDougall himself holds the responsibility of guiding the audience too.

From his very first frame, cinematographer Óscar Faura immerses us in Conor's experiences, the camera lens rarely - if ever - leaving his side. We're never told outright what illness his mother is suffering from or just how bad her condition really is. Things we do learn only come about through partially shut doors or whispers heard by Conor from other rooms, emphasising his loneliness. We, as much as him, are kept in the dark, making the situation hard to accept and all the more worrying. 

Where we do learn everything however is in MacDougall's face which changes from sadness and confusion to joy and wonder in the blink of an eye. His charming and nuanced performance perfectly sums up the complex emotions of pain and loss and how sometimes, there's no shame in breaking down in the face of adversity.   

Despite a lack of screen time, supporting cast Jones, Neeson and Sigourney Weaver are equally as solid. Confined to living rooms and hospital beds, Jones's scenes are full of warmth and encouragement towards her young son, their chemistry instantly palpable. Weaver's grandmother is much more stern - or so Conor thinks - with her 'old lady museum' house and rules against rucksacks in the hallway but as the film goes on, her walls break down and Weaver's performance is flawless.

A Monster Calls
Bayona's ambiguous ending will leave you deciding for yourself whether the Monster is merely a figment of Conor's imagination but in the film's beautiful final act, we guarantee you won't even care Focus Features / YouTube

Despite its low fantasy threads, A Monster Calls' true brilliance lies in its focus on humans and the not-so-extraordinary but often life-altering trials they have to face such as dissolving marriages, family upheaval and of course, death. And if any filmmaker has proved in their past filmography that they can juggle such sensitive subjects, it's Juan Antonio Bayona, whose past works include the sad The Orphanage and biographical drama The Impossible.

The film's visuals are just as impressive as its cast and crew, with the Monster's stories all illustrated as he narrates them to Conor. (And anyone who has seen Harry Potter And The Deathly Hallows Part 1 will already know the impact that segments that tell a story within the film can have on an audience). Dazzling, rolling watercolours tell morally-charged fables examining how people are often neither good nor evil or how things aren't always what they seem.

All in all,  A Monster Calls manages to combine fantasy and realism to create a story that deals with grief in a mature, respectable way that is sure to pull at your heartstrings. When wonderfully sweet links start being made between Conor's real-life relatives and the experiences he's shared with his gigantic and unusual counsellor towards the end of the film, every single detail starts coming together, offering up one last undercurrent of overwhelming emotion.

Don't expect to discover whether the monster is a figment of his imagination or not, mind you. While certain clues are there, Bayona ultimately allows the audience to decide for themselves whether the talking tree is real, heightening your involvement with the tale unfolding on screen. Either way, by the time the credits roll, it really doesn't matter whether the monster is real or not as the 'truth' becomes unimportant compared to how his presence -and the story on screen - has made you feel.