‘Boundaries’: A weed-infused family road trip doesn’t track

Boundaries opens with a woman named Laura (Vera Farmiga)  speaking to her therapist about the progress she's made undoing the damage done by her selfish, toxic father.

It's a typically good piece of acting by Farmiga, who gradually and amusingly shows that Laura is trying to convince herself about something that is obviously not true. The scene has a level of wry, subtle wit that, alas, writer-director Shana Feste does not manage to sustain in Boundaries, a road movie and shaggy-dog story (full of shaggy dogs) with sharp detours but an inevitable destination.

Laura herself is a collection of overly schematic quirks. She has a hopeless addiction to stray dogs, and her house is full of them – she lavishes love and parental affection indiscriminately, the inverse of a father who gave her no attention at all.

The dogs lead to comedic chaos in her home, and her misfit teenage son Henry (Lewis MacDougall) is meant to be part of it. He acts out at school, and is about to be expelled (not for the first time, we gather), and while this is played for laughs, it feels tonally wrong – the boy is meant to come off as a sympathetic outcast, but instead he seems hostile, antisocial, and a little cruel, attributes that show up in his artwork.

Into the middle of the mess comes dad (Christopher Plummer), with an offer Laura can't refuse – he'll solve all of her money problems if she agrees to go with him on a cross-California road trip in his vintage Rolls-Royce. Laura rebukes her father, says no to the trip 15 times, and then of course Feste jump-cuts to a scene of the adamant Laura behind the wheel, accepting the inevitable.

Plummer and Farmiga seem like a potential dream team, but the pairing instantly feels wrong – they don't scan as father and daughter, and Plummer's continental bearing seems ill-suited to his character's backstory, a California counterculture fixture and pot-dealing legend now delivering one last trunk full of marijuana to clients up and down the state.

This meandering trek provides opportunities for old-timers – Christopher Lloyd and Peter Fonda – to contribute comic vignettes that yield less than they seem to promise. Bobby Cannavale shows up as Laura's toxic ex, and we see that she swapped a selfish father for a selfish husband.

As Plummer humanizes his character, moving him from towering narcissist to irascible charmer, the story shoves Farmiga in the other direction. Laura scolds her father, then her ex-husband, and is left to act out repeated scenes of rage and disappointment that grow tiresome as Boundaries pulls up to its final stop.

Help arrives (too little, too late) for Farmiga in the form of Kristen Schaal, who plays Laura's sister, and they have some nice scenes together – registering as family in a way that Farmiga and Plummer do not.