In movies, thefamily road trip is typically used to serve up heaps of wackiness. Nothing ever goes right, no one ever gets along, and if there’s a dog, you can guarantee it will be cut to for reaction shots. Writer/director Shana Feste’s father-daughter-grandson drama Boundaries mostly eschews these trappings. But its cooked-up complications eventually run out of gas, and its destination is as snooze-worthy as driving 500 miles of highway. 

The cast, however, couldn’t be better. Christopher Plummer and Vera Farmiga play Jack and Laura, a dad and daughter who aren’t the best of friends because of Jack’s disappointment as a father. The usual reason is given—he wasn’t there for her—but it’s implied that it’s also because he smokes weed, though in what exact way this affected their relationship isn’t clear. 

At the beginning of the film, Laura isn’t talking to Jack, sending his frequent calls to voicemail. But the reason he’s calling, which she finds out when she relents and phones him back, is because he’s getting kicked out of his retirement home and has nowhere to go. (The home’s board accuses him of being a “man with low moral integrity,” apparently because he sells weed, too.) Naturally, Jack wants to stay with Laura. But she hands him off to her out-of-town sister (Kristen Schaal), and soon they hit the road in his old car with Laura’s son, Henry (Lewis MacDougall, A Monster Calls). We immediately discover that it was Jack’s idea to drive because he wants to do some dealing, hoping for an assist from his grandson. 

Feste injects a little black comedy into the first half, and though there are a couple of eye-rolling developments, her story mostly feels fresh. Laura bears all the scars of an unhappy childhood but also seems a bit loony at times (at least until she’s suddenly the voice of reason). Her defining trait, though, is being a compulsive animal rescuer. “It’s fucking disgusting,” an overnight guest tells her. But her dad and sister also have a soft spot for dogs, so the obsession isn’t criticized by anyone but the dude.

Christopher Lloyd, Bobby Cannavale, and Peter Fonda co-star and are fine in their bit roles. (And they really are bit. It would have been ridiculous if Sony had decided not to release the film because of Fonda’s recent tweet about Barron Trump.) But the central trio make the show, with Farmiga wounded yet fiery, the Scottish MacDougall pulling off a spot-on American accent, and Plummer being the usual charmer.

Boundaries doesn’t say much about dysfunctional family ties that hasn’t been said in countless other movies: With a little give and take—plus the realization that our time on Earth isn’t forever—even the most grievous of sins can be gotten past. It’s trite, but Feste has a great idea for the close. The last shots are individual ones of the cast smiling into the camera, which gives you a renewed fuzzy feeling toward their characters. And with that, a wobbly story is as easily forgiven as a lifetime of family hurt. 

Boundaries opens Friday at Landmark Bethes- da Row and Angelika Mosaic.