Jem spends the summer at her grandfather's house on Lake Eerie. She quickly makes friends with Nathan. In town they hear about the "Midnight Madness" competition. To take part in the competition, they have to be at least 13 years old and own their own canoe. Jem is 13 and Nathan is 12. Jem has to compete alone, but she doesn't have a canoe. Her grandfather has a canoe, but there is no way he will let her use it. They decide to ignore their grandfather and fix the canoe themselves. But someone or something wants to stop them, because the next day the hole is back. They fix it again and Jem joins the race. She quickly gets lost in the fog, and when the boat starts to sink, Jem realises that she is not alone...