Na Kyung-soo, a diver, is angered to learn that the Coast Guard is assigning responsibility for the death of a fellow diver during the Sewol ferry disaster recovery to Ryu Chang-dae, the representative of civilian divers, and charging him with manslaughter.

Author Juyoung recalls the moment when he saw the dragon's tooth – the traces of war. His memory deepens, and he visits Nuri to find traces of his dead student. People beyond time, all those memories of love allow us to live despite the traces of frozen wounds.