Quick: what's a good spell against boredom? After getting off to a nimble start with "Fantastic Beasts and Where to Find Them" in 2016, J.K. Rowling's five-part prequel to the "Harry Potter" series is already starting to feel like an almighty slog. While its predecessor was a fleet and frothy caper, "The Crimes of Grindelwald" is more like "The Matrix Revolutions" (2003): darker, denser, and a whole lot duller.

It's 1927, and raffish "magizoologist" Newt Scamander (Eddie Redmayne) is back in London, and subject to a travel ban after his destructive visit to New York in the previous film. Meanwhile, the evil Grindelwald (Johnny Depp) has escaped captivity, in a pre-credits sequence that suggests the action set-pieces won't be any more coherent this time around.

Every saga needs a good villain, but Grindelwald comes up a little short. All Depp brings to the table is a bad David Bowie impersonation and the desiderata of a veteran Hollywood A-lister: The end credits list three personal assistants and five "support staff" for the actor, which must be some kind of record.