After twenty-two-month-old Tommy Graser finds a severed finger and gives it to a policeman, Monk walks through the park with Tommy trying to retrace the child's steps. He finds no body or other incriminating evidence, but he does discover a surprising affection for the placid and intelligent toddler, who constantly repeats Monk's name and quietly submits to having his hands wiped when he touches "nature." A lab technician identifies the finger as that of a twenty-five-year-old man, and Monk deduces from a callus that the young man played the violin. After visiting the home of Daniel Carlyle, a musician who fits this description, Monk concludes that Daniel's mother and her other son, Jason, killed Daniel and that Jason is masquerading as his brother. Meanwhile, little Tommy is temporarily removed from the custody of his foster parents, and Monk surprises everyone, including himself, by volunteering to care for him for two weeks until his new adoptive parents can take him. With Tommy in tow, Monk and Natalie follow the Carlyles. After seeing them waiting for a pay phone to ring and Mrs. Carlyle crying on her son's shoulder, Monk arrives at a new conclusion, which is verified when he again talks to the Carlyles--Daniel has been kidnapped. Monk agrees to follow the kidnapper's bizarre instructions, which include delivering the $500,000 ransom fee in a garbage bag onto a rooftop while wearing only a bathrobe (and his shoes and socks). Unfortunately, Monk is distracted by a phone call from Julie, who is babysitting Tommy, and delivers the money to the wrong man. While Captain Stottlemeyer and Lieutenant Disher straighten out the mix-up, Monk resumes caring for Tommy. Controlled chaos and dirty diapers give way to more urgent matters when Monk realizes that Tommy has taken a tube of lipstick out of Natalie's purse--and inadvertently given Monk the clue that solves the case. After reading Tommy to sleep with a fairy tale about a heroic little prince who solves a mystery, Monk realizes that Tommy will never live happily ever after with Mr. Monk and sadly decides to give him up to his adoptive parents.