Michael Shannon and Imogen Poots are a good pair with nowhere to go in Frank & Lola

A lot of actors from the United Kingdom lose a certain musicality in their voices when they try on an American accent, but Imogen Poots, a combination starlet and workhorse who typically appears in three or four movies per year on both sides of the pond, has a way of making that flattened quality sound compelling. Her American, put to best use in Green Room, has a disaffected lowness, stopping just short of monotone. She perpetually sounds as if she could say something devastating at any moment, even if she doesn’t actually go through with it that often.

This half-zonked, half-sly quality makes Poots a surprisingly strong scene partner for Michael Shannon, an actor whose intensity doesn’t have to overwhelm everyone else in the room, but surely could if given half a chance. They’re paired in Frank & Lola, a sort-of romance that begins with sort-of mystery. It starts with Lola (Poots), a recent college graduate, and Frank (Shannon), an experienced chef, living in Las Vegas and already in a relationship together. How long they’ve been together, how they met, and other details are not immediately apparent. The careful avoidance of this backstory gives their early dialogue exchanges a theatrical quality.

It’s mannered, but not ineffective; these early moments have a mysterious, unforced tenderness. The movie opens with a sex scene, but feels even more intimate a few minutes later, when Frank and Lola are having dinner with her mother. Lola’s mother is played with maximum eyebrow-wriggling by Rosanna Arquette, seemingly under the assumption that the audience needs additional cues that this character is self-centered and inattentive to her daughter’s needs. One thing rendering the overplaying unnecessary is Poots’ performance in the scene, maintaining her composure while quietly conveying her irritation. Afterward, Frank and Lola discuss the dinner together in a car, Vegas neon reflecting in their respective windows in a series of one-shots, intercut with a scene of them together a little later. The actors and filmmaker bring a lot of affection out of a routine exchange.

That feeling doesn’t last, and even if that’s by design, it’s not a very good design. Slightly before the movie’s halfway mark, Frank heads to France for a job opportunity (provided by a bro-ish benefactor played by Justin Long) and, while there, tracks down a figure from Lola’s past, leading to a lot of scenes of Michael Shannon glowering his way through Paris. The Paris sequences are still well-shot, but they send Frank & Lola on a noirish path that doesn’t reward the actors’ commitment. As the movie’s initial mysteries dissipate, they’re replaced with seamier, shadier questions about Lola’s life before Frank. This might be more enticing if so much of it wasn’t conveyed through competing monologues that amount to an ongoing dispute between “this happened” and “no, actually, this other thing happened.”

Poots and Shannon share less screen time in this section, and the movie suffers for it. Ross never gets around to explaining how, exactly, a fortysomething chef whose brightest mood is only a few steps up from seething and a damaged twentysomething fashion designer decided they could complete each other—or even, really, how they fail to work out. The movie turns back into a romantic drama in time for its reflective final scene, but only just. In a trim 88 minutes, it manages to make Poots and Shannon an intriguing duo, then lets them revert to odd mismatch. It may be worth watching, though, for anyone who’s ever wanted to see Shannon attempt to burn holes in Justin Long with his eyes.