After more than sixty years in the business, it’s easier to pick the occupations and/or iconic film roles that Dame Maggie Smith has not played onscreen than it is to name the ones that she has. Spinsters and schoolmarms, Greek goddesses and grandmothers, maids and whores, nuns and royalty, Maggie Smith is so good at just about everything that she even won an Oscar (her second) for playing an Academy Award-nominated actress who loses the prize on the big night in 1978’s California Suite. That’s right, even when her character loses, Smith wins.

And though some critics (and fans) had a hard time swallowing the fact that Downton Abbey’s beloved Dowager Countess was playing a grubby, mentally ill homeless women in last year’s art house sleeper The Lady in the Van, if you ask me, Smith proved, yet again, that there really is no role she cannot play.

Based on Alan Bennett’s stage play of the same name, Van began life as a series of diary entries Bennett wrote for the London Review of Books based on his real-life “friendship” with a fiery, ill-tempered homeless woman named Miss Shepherd who lived in a van parked in Bennett’s Camden Town driveway for close to fifteen years. Bennett has described the experience of sharing space with the very difficult Shepherd for so many years as trying, at best, but his grudging fondness for Van’s real-life heroine shines through in Alex Jennings’ (The Queen, The Wings of the Dove) impeccable performance as not just one, but two versions of the author: Bennett the writer and Bennett the man.

And while I’m not generally a fan of stagey dual narrator conventions of this sort (especially on film), Bennett’s dry, darkly hilarious script and Jennings’ knockout performance won me over almost immediately. And anyone who writes for a living, or even works at home for that matter, will surely relate to Jennings’/Bennett’s habit of partaking in long, rambling conversations with themselves. There is a special kind of giddy madness that afflicts shut-in writers from time to time and Jennings captures it beautifully with his pithy, cantankerous dual performance here.

Directed by Bennett’s friend and frequent collaborator, Nicholas Hytner, who helmed the acclaimed stage and screen versions of Bennett’s The Madness of King George and The History Boys, Van also marks a reunion of sorts for Smith, who won raves for her performance as Shepherd in the original stage version of the play. Bennett/Hytner regulars like Tony-winner Frances de la Tour (Into the Woods, Harry Potter and the Goblet of Fire), Stephen Campbell Moore (The History Boys), Dominic Cooper (Mamma Mia!, The Duchess) and The Late Late Show’s James Corden round out the top-notch cast with UK television vet Gwen Taylor deserving special recognition for playing the other difficult woman in Bennett’s life, his aging mother, Mam.

And though Van is set in the 1970’s, the very real issues it raises about the root causes and societal impact of homelessness could not be more timely. Some critics complained that Bennett and Hytner sugar-coated the grittier aspects of Shepherd’s life in the film, but I found the exact opposite to be true. It’s not a documentary to be sure, but Van’s funny, pull-no-punches take on the subject is perhaps the most realistic depiction of onscreen homelessness I’ve ever seen. Turning the kooky, street Saint cliché of many cinematic depictions of the homeless on its ear, Van allows Smith to breathe genuine fire and venom into her performance and the film is all the better for it. There is no room for cheap sentiment or easy answers here, but if you’re looking for a frank, entertaining, and exquisitely drawn character study about two very different people trying to make sense of one another, Van is definitely right up your driveway.

Now playing on select British Airways, Air Canada, American Airlines and Delta flights worldwide, The Lady in the Van is also available via streaming at iTunes, Amazon Video and Google Play.