Roberta Glass is a bored and unfulfilled housewife living in New Jersey who becomes fascinated with the personal ads she reads in the newspaper. One ad, in particular, catches her attention—a series of messages exchanged between two lovers, Jim and Susan. Intrigued by their adventurous lives, Roberta decides to follow Susan and soon finds herself at Battery Park where she witnesses a rendezvous between Susan and Jim. Her curiosity grows stronger, leading her to purchase Susan’s jacket from a thrift store, inside which she finds the key to a locker containing valuable possessions. This small act of impulsivity embroils Roberta in a series of unexpected and dangerous events.

Confused for Susan due to her new possessions and attire, Roberta gets entangled with a variety of characters including Dez, a projectionist who decides to help her after she suffers from amnesia. Meanwhile, the real Susan, an elusive and carefree drifter, navigates her own chaotic journey, unaware of Roberta's existence. As these parallel lives weave closer together, Roberta unravels a web of mistaken identity, romance, and intrigue that challenges her sense of self and forces her to reevaluate her monotonous life. Past the midpoint, Roberta’s adventures reach new heights as the identities continue to blur and the stakes amplify.