Some ambitious young screenwriter should send Vin Diesel 100 plotless pages of dungeon-delving and dragon-bashing, as that seems to be the movie he's looking for. For now, we have The Last Witch Hunter, a $90 million supernatural time-killer that's mostly set in the here and now rather than in, say, Gary Gygax's Greyhawk, although the prologue is a not-bad nighttime RPG sword-and-sorcery adventure. Turns out 800 years back Diesel's character -- Kaulder -- got cursed, and now he's doomed to spend the rest of eternity stomping witches in Manhattan, a fate he finds enjoyable and highly remunerative.
Kaulder reports to some vague Witch Council, and he's partnered for centuries with helpmeet priests (Elijah Wood as the new guy; Michael Caine as the one in his last week before retirement), but the movie leaves it to you to work out the geeky specifics. Everyone involved knows the audience can grasp a fantastical setup on the fly.
Instead, Kaulder's off to the hunt. Witches live among us but aren't allowed to jack with humans; when they do, Kaulder collars them for the council's judgment. This time, Kaulder is investigating the death of a friend. What follows is urban-fantasy noir with crime scenes and clues and some inspired witchery. The joys are in the way director Breck Eisner, like Diesel, is earnest about this goofiness. His direction might not showcase the full wit of the script, but it does honor its inventiveness: its gummy-bear tree, its charred yet smoldering witch corpses, its descent into the writhing tree-roots of hell, some business with a pulsing ancient heart, and a flaming sword, which of course is named Hexenbane.