A young couple, Pippa and Thomas, move into their first apartment together in Montreal. They soon realize that their windows look directly into the apartment across the street, where a man with a professional studio is taking photographs of a woman. Pippa and Thomas watch as the couple have sex. Thomas continues to watch at first, but stops at Pippa's insistence. They jokingly give their neighbors pseudo names, Margot and Brent.Pippa, who works as a trainee optometrist at L'Optique, receives a bird feeder from her boss as a housewarming gift. Pippa buys a pair of binoculars so she and Thomas can watch the couple. They often see "Brent" having sex with several models while "Margot" is out.Pippa expresses interest in knowing what the neighbors are saying, eventually learning that Thomas knows a way to listen in on another room using a laser pointer; the process requires a reflective surface to send the laser beam back to them. When "Brent" and "Margot" throw a Halloween costume party in their apartment, Pippa and Thomas sneak in by posing as guests. Pippa plants a mirror in the apartment, later allowing her and Thomas to listen in on their conversations. They are unsettled to hear "Margot" confront "Brent" about his adultery; "Brent" assaults "Margot" and convinces her that her suspicions are unfounded.The next day, "Margot", whose real name is Julia, visits L'Optique where she receives an eye exam from Pippa and orders a new set of stylish glasses recommended by her. Julia invites Pippa to hang out. Pippa wants to warn Julia about "Brent's" adultery, but Thomas insists that she stop spying on the neighbors. Later, Pippa and Julia meet at a spa; Julia reveals that her husband is named Sebastian, or Seb, and is a well-known photographer.Pippa observes Seb having a threesome and throwing a condom away afterwards. She later discovers how to access Julia and Seb's wireless printer, which she uses to anonymously expose Seb's infidelities to Julia, mentioning the condom as proof. Thomas angrily confronts Pippa about being so invested in Julia and Seb's lives. The next morning, Pippa apologizes to Thomas and promises to stop watching the neighbors. However, they then see Seb discover Julia's body in the bathroom, after she seemingly slit her own throat. Thomas blames Pippa for Julia's death, breaks up with her, and leaves.Although heartbroken, Pippa continues to watch Seb and one evening decides to follow him to a nearby pub. Seb sits by Pippa and they talk. He asks her to let him photograph her at his apartment, which she accepts. Seb convinces Pippa to pose nude for him, and they eventually have sex. Upon returning home, Thomas consumes a drink Pippa left in the refrigerator and pours it into her bird feeder. He notices Pippa having sex with Seb across the street. The next morning, a horrified Pippa finds Thomas dead in their apartment, having apparently hanged himself.Pippa and her friend Ari go to Seb's exhibition, which turns out to be a collaboration with Julia, who is alive. Pippa and Thomas are revealed to be the subjects of the exhibition. Seb and Julia divulge that they own the apartment rented by Pippa and Thomas (whose lease included a clause stating that they consented to be photographed), and they knew they were being watched. Distressed, Pippa storms off. She decides to move out of the apartment, and notices dead birds on a grate just below her bird feeder.Following an interview promoting their exhibition, Seb and Julia return home to find a congratulatory bottle of wine by their door. As they drink the wine, Pippa sends a message to their printer saying she knows they killed Thomas. After leading Seb and Julia into L'Optique, Pippa deduces that while she was having sex with Seb, Julia poisoned Thomas's drink and staged his suicide. Pippa also reveals that she spiked their wine, causing Julia and Seb to faint. Pippa places the two under a LASIK machine, using it to burn their corneas.A new couple have moved into Pippa and Thomas's former apartment. They observe Seb and Julia in their apartment, both of whom are now blind. Pippa watches Seb and Julia from the rooftop, before leaving her binoculars behind. (copied from Wikipedia)