Stuart "Stu" Shepard (Colin Farrell) is an arrogant New York City publicist who has been courting a woman named Pam (Katie Holmes) behind his wife Kelly (Radha Mitchell). He uses the last remaining public phone booth in the city to contact Pam. During the call, he is interrupted by a pizza delivery man, who attempts to deliver a free pizza to him, but Stu rudely turns him away by insulting his weight. As soon as Stu completes his call to Pam, the phone rings. Stu answers, to find that The Caller, who knows his name, warns him not to leave the booth, and says he will say hello to Pam for him. He also says he will call Kelly, leaving Stu panicked.