On the eve of Vermont's Great Flood of 1927, rain falls on northern Lake Champlain. Otter's father has been missing since World War I, and then a letter arrives with surprising news. Royal St. Onge may be alive! Otter and Granddad load a canoe with Mississquoi Moonbeam and paddle across Goose Bay to rendezvous at the family camp, but Otter's father is nowhere to be found, and bullet holes scar the cabin walls. The trail finally leads to a cutthroat gang called the Crows who will kill every member of Royal's family unless Otter can stop them.