stars as Mace Sowell, an ex-DIA agent who believes his life is in danger from his former boss, Admiral Thomas Michelmore, who is now running for President of the United States. Sowell has information about the underhand dealings of his erstwhile boss at the DIA which would ruin his Presidential campaign if it ever was released into the public domain. The information is located in cyberspace and is scheduled to be sent to every major newspaper in the western world unless Sowell reprograms the mail server remotely from his computer every 24 hours using a special password only he knows. To complicate the issue, Sowell is in the early stages of Alzheimer's disease and has difficulty in convincing people his information is not paranoia as a result of his condition. Sowell retreats to the safety of his barricaded home, kitted out with a variety of defenses and security devices to try to escape those he thinks are out to harm him. Kimberly Williams plays the part of Andi Travers, his caregiver. Mace is initially extremely hostile towards Andi and only agrees to allow her to live and work with him as his daughter threatens to have him committed. For the same reasons, he visits a Psychiatrist Dr. Simon but only after taking heavy precautions such as disguising himself as a Rabbi or Telecoms worker. He is unable to convince his Psychiatrist or his daughter and her partner of the truth of the threat he faces, partly due to the fact that he never discussed his career in the DIA with his family and also because paranoia is a common symptom of Alzheimer's disease. Mace keeps a daily video log in his private study to track the progress of his 'operation' and also monitor his mental health, usually while working out. More and more, he uses post-it notes tacked to the walls of the house to remind him of certain tasks, a visible indicator of the progression of his disease. He subjects Andi to a full background check but finds nothing suspicious. Their relationship is fraught at first as she tries to convert Mace to a macrobiotic diet. She also becomes enraged when she finds out that Mace has security cameras in every room of the house including her shower and that he has searched her underwear drawer. Mace doesn't seem to have very many friends however he is close to Stu, a man who cleans his pool and does other odd jobs for him. Stu tells Andi that he has known Mace since before the onset of his mental degeneration. Stu often likes to impersonate Humphrey Bogart and Robert de Niro. Amongst the jobs Stu carries out or Mace are drills — training exercises whereby Stu dresses up in quasi-military gear and balaclavas and simulates breaking into Mace's house and attacking him. Stu does this more out of friendship and lack of anything better to do than because he believes Mace's claims about being under threat. During one such drill Andi mistakes Stu for a genuine burglar and severely injures him with a golf club. Mace's daughter Michelle chooses to call the house at this point to check on her Father and Andi covers for Mace saying that everything is fine, for which he is grateful. Mace slowly begins to trust and depend upon Andi as his mental faculties continue to deteriorate. In the end, Andi gets the drop on Mace, revealed as an agent for Michaelmore. Mace expresses admiration to Andi for being able to fool even him. He attempts to find a gun, but finds that Andi has long since removed or disarmed many of the traps he had placed in his home. He finds one that she missed, a gun hidden beneath the kitchen sink, and shoots her. In his last action of the film, Mace sits at his computer and sends out the information he had kept hidden to news organizations worldwide, one of his last acts of clarity as he succumbs almost completely to his disease.
