Montreal is in the grips of one of its summer heat waves, when searing temperatures have a way of making its residents cast aside their better judgment. A young twenty-something works the night shift at a call center, her only company the disembodied voices of the customers who call in to complain. She spends her night off drinking with her friend Louis at "their" bar, while her successful boyfriend sleeps. His career allows her the pleasures of his spacious, modern condo, a new existence. She likes feeling undefined, still up for grabs, even as the middle-class trappings of her relationship threaten to shape her. In the stifling humidity of such surroundings, her life is turned upside down when she grows obsessed with Mia, a beautiful woman she meets one night at the bar. Then there's the woman who's gone missing, whose face is constantly on screens across the city. How can she stem the drift away from her relationship, she worries, when her former lover B., who was both violent and magnetic, is always in her thoughts? All these orbits are set to collide, as the heat wave shows no sign of breaking and emotions reach record highs.