When we first meet Luke and Emily, they couldn’t appear more perfect and well-suited for one another. After their secret workplace romance blooms into a wholesome, committed relationship, Luke proposes, and the two seem excited about announcing the news to the world eventually. In their shared workspace, the prospect of a promotion to the role of PM makes Luke giddy about a life of respect and comfort for the both of them, but when the promotion unexpectedly goes to Emily, the crux of their relationship is suddenly jeopardized, as Luke is no longer kind or supportive towards his partner. As time passes, he becomes increasingly bitter and vile.
The heart of the promotion fiasco is that while Luke perceives Emily’s promotion as unexpected and in his mind, unfair, it was an inevitability from an objective standpoint. Immensely smart and capable, Emily had been an asset to the firm for years, and it was only natural that her superior, Campbell (Eddie Marsan), immediately considered her for the role of PM. Luke was never in the running, to begin with — if anything, his hiring was a favor, his presence in the firm was tolerable at best, and his frequent attempts at proving himself led to revenue losses on more than one occasion.
Just like any mediocre and deeply insecure man would, Luke asks Emily if her promotion was the result of Campbell making sexual passes at her or her granting him sexual favors. Not only is this a display of abhorrent sexism but also genuine disrespect towards Emily, who constantly tries to make herself small to accommodate Luke’s fragile male ego, until she decides to snatch her autonomy back. The outcome is not only unpleasant but extremely painful and bloody.