The sides are steep, the water's deep,From bank to brae the water's pouring,And the bonnie grey mare she sweats for fear,She stands to hear the water roaring. As he rides along the unexplored green lane beyond the wired-up gate, fifteen-year-old Michael finds a brief respite from the pressures of school and the family horse-dealing business. At the end of the lane he meets Annie, who is destined to bring colour and warmth into his troubled life. Between her home and Michael's lies the Annan Water, a deep and mysterious river. In its dark past, and in the old song about it, there are warnings that their love for each other will end in tragedy. Can it be true?