Peter (Aaron Paul, left) disappears after his precocious son, Louis (Aiden Longworth), falls into a coma in “The 9th Life of Louis Drax.” (Doane Gregory/Summit Premiere)

A comatose boy communicates telepathically with his doctor in the mystery “The 9th Life of Louis Drax.” Adapted from a 2004 novel by Liz Jensen, the film is a benign departure for director Alexandre Aja, who specializes in such horror movies as the brutal 3-D remake of “Piranha.” Unfortunately, this film’s dark premise is drowned in whimsy and a forced childlike wonder.

Plenty of movies feature precocious children, but Louis (Aiden Longworth) is one of the less believable: Would any 9-year old boy in 2016 write threatening letters on a typewriter? Describing himself in a voice-over as “the amazing accident-prone boy,” Louis has, in his short life, survived eight accidents. But the film’s portrayal of these accidents is so twee they’d make Wes Anderson roll his eyes, and the boy’s narration is so precious that it’s hard to care when he plunges into the sea. After this ninth accident, the boy’s abusive father, Peter (Aaron Paul), disappears and is suspected of pushing Louis. Yet the truth is more complicated.

While “9th Life” revolves around an unlikable child, the adults who surround him aren’t much more believable, from his ineffectual mother, Natalie (Sarah Gadon, who was much better in “Indignation”), to a doddering child psychiatrist (Oliver Platt) to Dr. Allan Pascal (Jamie Dornan), a specialist in pediatric comas who falls in love with Natalie. Despite his brusque manner, Peter may be the film’s only sympathetic character, because Paul’s performance is the only one in the film that resembles a human being.

Dornan fares especially badly, his line readings flat and his facial hair tailored in a way that makes it seem as if the filmmakers would have preferred to cast Mark Ruffalo, whose aw-shucks persona might have made this work. Yet Dornan never makes his admittedly underwritten character real, oddly coming closest when he channels the thoughts of a 9-year-old boy.

“The 9th Life of Louis Drax” throws childhood fantasy, adult melodrama and a quasi-scientific thriller at the viewer, and none of it sticks. Early in the film, Louis explains that he was clinically dead for two hours. By the time it’s over, that seems like a fate more easily endured than the movie.

R. At area theaters. Contains strong language and scenes of childhood endangerment. 108 minutes.