While on a business trip in Los Angeles, Mary is unaware that her husband Michael is having an affair with a hotel maid, Lucy. As their lives intersect, Lucy has a hidden agenda to ruin their marriage.
Michael is caught off guard when Mary unexpectedly returns to the hotel room during his rendezvous with Lucy. He tries to cover up, but Mary’s suspicions grow. Meanwhile, Lucy plans her revenge. As she helps Mary view hotel security footage, the evidence of Michael’s infidelity is nearly revealed, but the conversation distracts Mary.
Later, Michael, under pressure from a blackmailer, siphons money from Mary’s account to pay off the extortionist. However, Lucy’s true intentions are uncovered: she is the sister of Samantha, a former maid who was wrongfully dismissed by Michael after a misunderstanding. Samantha’s tragic death motivates Lucy’s revenge.
In a final confrontation, Michael is caught, and Lucy reveals the truth behind her actions. She walks away, satisfied with avenging her sister and donating the ill-gotten money to charity.