THERE IS A LONGSTANDING notion that a playwright should exhibit some degree of eccentricity. Alan Bennett (played here by Alex Jennings) does so by allowing a cantankerous homeless woman to live in a van parked in the driveway of his London home for 15 years. (In other regards, he's the author of The Madness of George III and The History Boys.) That woman, Miss Shepherd (played by Maggie Smith, turned up to 11), outstripped her begrudging host in eccentricity—she had casual conversations with the Virgin Mary, boasted a tongue rude to the point of hilarity, and had an inexplicable insistence on painting everything mimosa-yellow—if not resourcefulness. With the Nicholas Hytner-directed The Lady in the Van, Bennett has brought the total number of sellable versions of their story up to four: one book, two theatrical productions (one for the stage, one for radio), and now a film. It feels less certain to say that the story has the merit to sustain all these iterations than to credit Smith's performance in three out of the four.

For diehard fans of Smith's signature fish-eyed, thin-lipped severity, Van may as well have been topped with a bow. As bits of Miss Shepherd's backstory leak out in dribbles during the plot's otherwise lackadaisical proceedings, she emerges as a nasty but vulnerable wit. Educated, talented, but psychologically damaged (Catholic nuns come off poorly), Shepherd manages nobility despite being someone who strews her feces around the yard. Meanwhile, Bennett is possessed of a dry, shy humor, and a device portraying him as twinned—two versions, "one who does the writing and one who does the living," conferring with each other much like a married couple—works surprisingly well.

Comfort food for Anglophiles, Van is aimed at those with a chummy affection for English smugness disguised as self-deprecation, and abiding allegiance to Smith as a National Treasure. Others will find it somewhere between adequate and annoying, and few will appreciate the rushed, silly ending that should shoo away any remaining reason to further belabor this story's retelling.