Compulsion unfolds the intricate journey of Anjika Indrani, a privileged young graduate from Cambridge who finds herself entangled in a concealed romance with her fellow graduate, Alex. As tensions rise in her family, her father, Satvick, exerts pressure on her to enter an arranged marriage with Hardick, the son of a business associate. Amidst this turmoil, Don Flowers, the family’s chauffeur, becomes aware of Anjika’s unhappiness concerning her father’s decision. He offers her a solution, albeit with a shocking condition: he demands that she spends a night with him. Initially repulsed by the idea, Anjika finds herself reluctantly agreeing to this arrangement.
As events unfold, Hardick unexpectedly collapses during a date, providing Don with an opportunity to manipulate the situation by taking Hardick to his flat, where he strategically places illegal drugs to paint Hardick as a dealer. This swift action leads Anjika's parents to cancel the marriage plans, but Don reminds her that she still owes him for his help. Torn by her circumstances, Anjika visits Don in the hotel room he secured, allowing him to flirt and touch her, culminating in a night of intimacy that both alters their relationship and complicates her life further.
Anjika begins to weave a web of excuses, claiming that if Don ceases providing her brother with drugs, she will once again be with him. Their passionate affair blooms, and despite the love and connection that grows between them, Anjika struggles with her feelings as her parents support her relationship with Alex, even planning their marriage. The reality sets in for Anjika as she grapples with her affection for Don, who is significantly older, leading to an inner conflict where she attempts to convince herself that her love for Alex remains true.
However, Hardick's return brings chaos as he directs his anger at both Anjika and Alex, eventually confronting Anjika and Don in a moment of peril. In a gripping twist, Hardick's wrath leads to violence when Don intervenes, resulting in a tragic death that alters the course of Anjika’s life dramatically.
As Anjika’s tangled affair with Don persists, he gifts her a bracelet, yet she feels unworthy of wearing such a token. Moments of escapism at a nightclub lead to further complications when a flirtatious text intended for Don is accidentally revealed to Alex. Anjika, desperately trying to deny her feelings for Don, experiences heightened stress as she realizes the depths of her entanglement.
In a climactic turn of events, Anjika prepares for what she initially envisions as a final date with Don, armed with a knife and fraught with hesitation, fearing the implications of their relationship. The night culminates in a chaotic and tragic moment where the line between love and despair blurs, forced into a climactic confrontation that ends in violence. Anjika dials the police, professing herself the murderer of a rapist in a desperate act of self-preservation.
Ultimately, the film ends with Anjika and Alex emerging from their wedding, where she displays a facade of happiness despite her internal turmoil. Clutching a bracelet gifted by Don, her ambiguous expression hints that her heart may still belong to him. As she glances at the new chauffeur entering the front seat of their car, the sorrow in her gaze suggests that her true love for Don lingers beneath her carefully constructed exterior.
