Forget all the heist movies in which thieves steal humdrum things like diamonds or Monets or coaxium. The big score in American Animals is something to get really excited about: rare books.

Based on a true story about a plot to relieve the library at Kentucky’s Transylvania University of its most valuable tomes (including a drool-worthy Havell edition of Audubon’s Birds of America), director Bart Layton’s first foray into scripted filmmaking is an odd mash-up of his usual documentary style and narrative storytelling.

Most of the time, the mixture works. The scripted, acted parts of the movie—which make up its bulk—are fully engrossing, and although Layton’s stylistic decisions are colored by familiar Scorsese and Kubrick influences, more often than not, the result is zippy and fun.

Layton is also well aware of the countless heist movies that have preceded this one, and the film’s riffs on the genre add levels of unexpected complexity and sadness. These four young thieves were raised on Hollywood-glorified visions of crime, and American Animals exposes the aimlessness and emptiness at the heart of their caper.

The performances are great, with a well-drawn, unconventional relationship between the two ringleaders, impulsive, bro-y Warren (Evan Peters, better known as “Quicksilver” in the X-Men movies) and thoughtful, artsy Spencer (Barry Keoghan, better known as “Doomed Sweater Lad” in Dunkirk). Jared Abrahamson and Blake Jenner, as their accomplices, are similarly effective.

Which makes me wonder if Layton should have jettisoned the film’s documentary elements entirely. It’s instructive, certainly, to see the real-life perpetrators and their families in interview segments, and their presence ensures that the more unbelievable elements of their harebrained scheme are, in fact, authentic, but sometimes the juxtaposition jars.

Still, American Animals is interesting and entertaining enough that these questions just make me want to see it again.