The worldwide search for damaged personalities about whom to make feature-length documentaries has come up with arguably the strangest yet: Henry Darger, the reclusive, ignored, and utterly isolated janitor who, on his death in 1973, turned out to have been scribbling and painting obsessively for decades in his Chicago bedsit.

Jessica Yu's film dips a toe in Darger's world-view - one dominated by visions of hermaphroditic children fighting a gruesome civil war in the name of Christianity - and it's certainly extraordinary stuff, made all the more so by animated sequences bringing Darger's illustrations to life.

Darger could be a modern William Blake; that said, he remains an elusive figure: partly because he can't speak for himself, and partly because Yu makes no more than superficial attempts to understand someone clearly suffering from a serious personality disorder. Asking bratty child star Dakota Fanning to speak the voiceover is an especially creepy touch.