The immortal Vin Diesel, doing something spectacular. Photo: Lionsgate

The Last Witch Hunter is so dense, so packed with stuff — with spells and strange beings and dreams and weapons and ornate walls and tree roots tangled with skulls and giant swirling apocalyptic black clouds of man-eating flies — that you might not notice at first that there aren’t any people in it. Vin Diesel plays Kaulder, a beefy, bearded warrior we first meet sometime in the Middle Ages, as he kills the ghastly Witch Queen (Julie Engelbrecht). Witches, you see, are real, and they were responsible for the Black Death, and Kaulder and others have been hunting them for some time in an effort to avenge their loved ones. Right before she turns into a pillar of ash, the Witch Queen puts the curse of immortality on our hero. “I curse you with life! To never know peace! To walk the earth for all eternity!” So he was maybe an average Joe witch hunter once, but now he’s an immortal.

The film then flashes forward to many centuries later, and Kaulder, still alive after all these years, now shorn of his beard and looking for all the world like Vin Diesel, is on an airplane hitting a strange bit of turbulence. He sniffs out a young witch on the plane, but he lets her go with a warning. (Then he seduces a stewardess, but I digress.) We learn that witches are now allowed to govern themselves, so long as they don’t hurt people, and that Kaulder has been policing them all these hundreds of years. His only companions are a long line of priests, all called Dolan. The 36th Dolan, played by Michael Caine in full-on Alfred Pennyworth mode (“You’re missing a great part of your life. The part where you share it”), is preparing to retire, and the job of guiding and redeeming Kaulder will fall to a young novice, played by Elijah Wood.

While the world Kaulder inhabits is supposedly our own, the figures he comes across are all variations on fantastical beings, all in on the game to some degree. The priests are mortal, sure, but they’re also centuries-old companions and keepers of dark secrets. Kaulder soon matches up with Chloe (Rose Leslie), a shape-shifter (that’s a kind of witch, apparently) who runs a Memory Bar and can enter people’s dreams. There’s also Belial (Olafur Darri Olafsson), an evil witch who longs for the days of the Witch Queen, before the uneasy truce. And Ellic (Joe Gilgun), another shape-shifter who lures young kids to their doom. And a blind merchant played by the seemingly always-underused Isaach De Bankolé. Nobody knows everything, but everybody knows something; they’re all role-players. That’s probably the idea: Diesel, an avid Dungeons & Dragons fan, previously expressed his desire to create a movie that fits into that kind of experience — where everyone has powers and understands the game at hand.

That, unfortunately, doesn’t leave much room for us. There’s no one here to show some wonder or curiosity as a way of bringing us into this story. Chloe presumably plays the role of ingenue, but even she’s basically a powerful witch, and Leslie gives her an opaque calmness; the young Dolan, meanwhile, doesn’t get much to do (save for some business at the end, which I won’t spoil). There’s enough production design onscreen to suggest that The Last Witch Hunter’s universe has been deeply imagined by somebody somewhere, but it doesn’t translate in any dramatically interesting way. We keep finding out about new beings, and new sub-beings, and new powers, and new spells, but without a compelling drama to attach themselves to, the revelations feel inconsequential. Watching The Last Witch Hunter is like sitting by while someone else plays a game whose coolness eludes us.