Stuart Shepard (Colin Farrell), a publicist in New York is having an extra-marital affair with Pamela (Katie Holmes). In order to keep his wife Kelly (Radha Mitchell) in dark, he daily uses a public phone booth instead of his mobile to call Pamela. One day, the phone in the booth rings while he was inside and he casually picks it up. This turns out to be a big mistake. The caller threatens to kill Stuart if he hangs up the phone. The laser beam from his rifle proves that he is not joking. He has a lot of information about Stuart and is aware of how he cheats his wife. He wants Stuart to publically confess in front of his wife which Stuart obviously denies. The events that occur unfold how the caller punishes corrupt people either by making them admit their sins or killing them. You have to see the movie to know how Stuart handles this situation.
