The relationship drama takes a thrilling new turn in Chloe Domont’s debut feature, Fair Play, which premiered at Sundance on Friday night.

In one version of this story, it should be the best week of Emily’s (Phoebe Dynevor) adult life. She’s newly engaged to Luke (Alden Ehrenreich) and has just gotten an incredible promotion at the hedge fund where she works as an analyst. Instead of celebrating, though, Emily finds herself dealing with the bruised ego of her new fiancé. They have been dating in secret for two years since their company has a policy against intraoffice relationships. And her coworker/future husband had his sights set on the position Emily just got.

If Fair Play concerned itself only with the precarious balance of emotions and ego between lovers in a fiercely competitive industry, it could have been a perfectly good movie. As women rise through the ranks of male-dominated industries in greater numbers, there is a natural shift in relationship dynamics. There is plenty to say about this and plenty of films have already done so.

Instead, Domont’s script and tight direction turn this into a sharp and incisive thriller in which the central relationship is the major but not only important part of the story. We first meet Emily and Luke at his brother’s wedding. The two hopeless, drunk, and frisky lovers sneak off to the bathroom for a quickie that gets interrupted by an awkwardly amusing and portentous situation when something falls out of Luke’s pocket. He’s been waiting for the right moment to propose. Domont’s introduction of the carefree pair, thoroughly and enthusiastically in love, leaves us with the sense that nothing could possibly come between them.

And then it does.

The environment at Crest Capital is as cutthroat and toxic as one might imagine of any flashy Wall Street investment firm. Quinn, a portfolio manager (PM) is fired and then trashes his office with a golf club before being escorted from the building. His dismissal leaves a hole in the management team and Emily overhears a rumor she can’t wait to whisper to Luke: he’s getting the promotion.

Except that he doesn’t. In the middle of the night, Emily is summoned by another PM, Rory (Sebastian DeSouza) to meet for a quick drink. When she arrives, Rory is gone but the company’s owner, Campbell (Eddie Marsan), is there and tells her the job is hers. Luke handles the news as well as we might expect, which is to say poorly. He smiles, he congratulates her and says it’s great news. But the smile is superficial and he almost immediately starts unraveling.

Phoebe Dynevor delivers a strong performance as a smart, capable woman finding her voice in a workplace dominated by men. It is very much the kind of “locker room talk” environment one would expect from a firm where millions of dollars flow in and out, everyone is fighting to get ahead, and the guys are used to working without women around. Dynevor’s Emily is compelling as she navigates the high pressure meetings, whisperings among subordinates, and the whiplash when her big cheerleader, Campbell, suddenly and viciously turns on her when she makes a bad call after listening to, of all people, Luke.

Equally strong is Alden Ehrenreich as Luke. As he descends into despair and self-pity, he begins to reveal facets of his personality that Emily never knew existed. Luke questions Emily’s late-night phone calls and meetings. He makes passive-aggressive comments about her wardrobe and demeanor and rejects her attempts at everything from conversation to sex when they are home in their shared apartment. Ehrenreich embodies Luke’s casual and then targeted misogyny, doing so much with the increasing desperation of a man on the verge of throwing everything away because of his sense of entitlement.

Domont’s script sizzles with crisp, biting dialogue and tension. She doesn’t define the terms or explain things like investment strategies or corporate jargon. Instead, she trusts the audience to follow along and we do. We don’t need to know anything anyone is talking about, we only need to know that it matters. When multi-million dollar deals hang preciously over Emily’s and Luke’s heads, we understand as much as we need to in order to know this could all go very wrong any minute.

Like an extra long fuse on a stick of dynamite, we watch in awed trepidation. Blending tones and textures of high-powered corporate culture from films like Margin Call, Boiler Room, Wall Street, and, in perhaps less obvious ways, Disclosure, Chloe Domont delivers an impressive and exciting debut.