[1] Katherine Lewis, having been a dentist since her late father and grandfather had each been one, is killed after being struck by a bike messenger.

Katherine signs a contract to be the Tooth Fairy and is trained by a worker named Raul on how to perform her service.

Katherine comes to visit Bobby again that night and discovers that his mother had died of cancer and his father, Thomas is always busy at work.

Katherine decides to help Bobby and his friends at his school with their problems, which lands her in trouble with the higher-ups in Limbo, as revealing herself to living humans is a grievous infraction.

Katherine feels that the children's needs are greater than hers and asks for Raul's help in making her visible to the parents and the school principal so she can prove that she is real and Bobby is not insane.