March 15 is the day that every child fears - the day where Mr. Crocker is at his meanest, and the reason of his extreme unhappiness remain a mystery, so Timmy uses the Time Scooter to go back to Crocker's childhood to solve it, and try to fix it. After exploring several different decades and time periods in his school teacher's life, Timmy finds a shocking secret that involves Crocker and fairies.