Among the several pleasures of writer-director Paul Weitz’s new film Grandma is watching Lily Tomlin drop a petulant teenage slacker to the floor with a hockey stick to the nuts. The aggression is not unfounded: Elle (Tomlin) is simply avenging her newly pregnant granddaughter Sage (Julia Garner), who is trying to collect enough money for her abortion appointment, and her baby daddy (Nat Wolff) won’t cough up his share.

That, in short, is the plot of Grandma. Elle, a misanthropic poet and recent widow who’s just broken up with her hot young girlfriend Olivia (Judy Greer), drives around madly, her 18-year-old granddaughter in tow, as the unlikely pair attempt to scare up $630 for Sage’s procedure that afternoon. This might be the least epic road movie of all time (especially with a running time of 78 minutes), but the results of the journey are nonetheless profound — hilarious, startling and moving.

As Elle and Sage tool around town in Grandma’s 1955 Dodge Royal, their comic misadventures become quixotic moments that unlock pieces of the dramatic puzzle. At one point they stop to hit up Elle’s lover of 30 years past, Karl, played with exquisite restraint by Sam Elliott; the old flames share a joint and a kiss, after which the soft-spoken Karl turns the screw, asking Elle what she really needs $500 for. Their negotiation erupts into acrimony, revealing dark secrets that mirror Sage’s current situation.

Weitz’s direction is gentle and intimate, honing in close to Sage and Elle and their burgeoning relationship. Grandma feels like a really good short story — it unwinds itself in emotional shorthand, never wasting a moment on undue particulars. Perhaps not enough time is given to Marcia Gay Harden, who plays Sage’s high-achieving mother, Judy, though this isn’t a major mark against the film that — similar to Zach Braff’s fantastic Garden State — picks a single emotional tone and develops it beautifully.

And Tomlin is at the top of her game here. Her fierce exterior, foul mouth and slapstick bursts of anger are the armor behind which mourns the recent death of her longtime lover. Tomlin’s Elle is all piss and vinegar, an eccentric old lady given to smart, nasty outbursts, but her granddaughter’s crisis brings her out of herself. Called to duty, Grandma is a weary warrior — part bitch, part nurturer, and ready to rumble. 

Grandma opens Friday, Sept. 18, at Bijou Art Cinemas (492 E. 13th Ave.).