In 1699 William Milmullen took his six pupils to the lake to study, but only William returned after a creature rose up from the water and devoured the six boys right before his eyes. After he’d recovered from the shock of what he’d seen, William Milmullen named the creature The Mourn and declared himself Mourner and vowed that every Milmullen would take the mantle of Mourner at the age of 16, to protect the town from “the dragon in the lake.”

In the story, Tim Milmullen is turning 16, but he doesn’t know if he wants the role of Mourner. For one thing all the kids at school make fun of him. But Tim’s biggest problem is that he isn’t sure if he believes in the legend or not. How can he dedicate his whole life to something he has never seen?