Eli is a 2019 supernatural horror film directed by Ciarán Foy, who previously made Sinister 2, released on Netflix with a budget of around eleven million dollars and a runtime of ninety-eight minutes. It stars Charlie Shotwell as Eli, a young boy with a severe autoimmune disorder, alongside Kelly Reilly and Max Martini as his parents, Lili Taylor as Dr. Horn, and Sadie Sink as a local girl named Haley. I want to be fair to this film, so I will begin with the single genuinely positive thing I have to say about it, and then we can move on together.

That positive thing is the twist, which I did not see coming in any capacity. "The sickly child at the centre of this film is the secret son of Satan" was not on my bingo card, and I have to respect the sheer audacity of it. Credit where credit is due.

Now, the rest. The setup follows Eli, whose condition means he cannot go outside without a full protective suit, being taken by his parents to a remote, sealed medical facility for an experimental three-stage cure. If that premise sounds familiar in a slightly unexpected way, it is because this is functionally Bubble Boy, the Jake Gyllenhaal comedy, except stripped of all joy and with substantially more screaming from its lead. The first hour operates as a fairly standard haunted house film, with Eli seeing ghosts, finding clues, and being told by Haley through the window that the facility is not what it appears to be.

Then the third act arrives and the film detonates. The full reveal is genuinely wild: Rose could not conceive, felt that her prayers to God were going unanswered, and so began praying to the Devil instead. It worked, and Eli is the Antichrist. Dr. Horn, meanwhile, is not a doctor at all but a nun leading a small order, and the "treatments" have in fact been a staged, multi-stage exorcism intended to drive the Satanic influence out of him. Three previous children have already died in this process. Eli's response, once he understands what has been done to him, is to telekinetically fold the nurses into crucifix shapes and set them alight, before turning on his own parents.

Kelly Reilly, whom many will know from Yellowstone, is here as the mother, doing devil-related business with a straight face. She is a genuinely good actress and I have no doubt her reasons for signing on were sound and probably numerical.

One detail I only assembled after the fact concerns Sadie Sink, who plays Haley. I watched her just days ago as the telepathic villain in the new Spider-Man film, and she turns up here as Eli's half-sister, delivering my favourite line in the entire movie: a breezy explanation that "Dad gets around." It is a genuinely funny piece of writing in a film that otherwise takes itself extremely seriously, and it implies a much more interesting story happening somewhere off screen.