It's the Summer of 1967. The sun shines brightly over Boundary Pond, a lake on the US-Canadian border. Holiday makers enjoy the summer, happy and carefree. Zaza Mulligan and Sissy Morgan play in the hot sand. Children run along the beach as the hours tick away to the sound of the radio blaring out the latest hits and the smell of barbecues. Life seems idyllic. But then Zaza disappears, and the skies begin to cloud over...