The series begins with a girl entering a gorge during a party and finding the skeleton of a guy who was killed many years ago.
Then she returns to the past and, in his body begins to live his life until the moment of his murder. In parallel with her life, she is also trying to find out what happened to him. I do not remember exactly, but it seems that she began to live in his body when she fell asleep.
I remember that this guy was a musician and, in the past was friends with her parents, they played in the same musical group. Her father even had a crush on him when he was a teenager. Together they went hiking in the mountains and slept in a tent. I also remember that they had an audition, but when she was in his body in the past, it was unsuccessful.
I remember at the end that the killer was not even one person, but many people who were now adults, and they hid the cause of his death.