German Aaron has found the woman of his life in his French girlfriend Lea, but her young son Tristan still imagines his mother reconciling with his American father. On what should be an idyllic vacation in the soaring Italian Dolomites, Aaron fights to win over Tristan and cement his place in this family, while Lea wrestles with conflicting loyalties to her son and her lover. When Tristan disappears into the mountains, it's unclear who is in the most danger.