Tony Shalhoub, Traylor Howard, Jason Gray-Stanford, and Ted Levine reprised their roles as the main characters from the show. Set twelve years after the series finale, the film follows Adrian Monk, a private detective with obsessive–compulsive disorder and multiple phobias, who comes out of retirement.
Adrian Monk, a San Francisco Police Department detective, has a nervous breakdown after his wife, Trudy, is killed by a car bomb. He loses his job and refuses to leave his house for four years. With the help of his nurse and assistant, Sharona Fleming, he begins work as a private detective and consultant for the police. Monk is afraid of 312 things, including germs, milk, ladybugs and ladybugs. He also has a brother Ambrose and half brother Jack Jr.