Redemption: the third party

This novel tells the story of her sister's rescue of her sister Yang Jingting, who died in an accident, using the timetable to go back to the past and save her sister. But I didn't live to be over 30< Br> knowing that she could not save her sister, Mei Mei saved a male high school student who also died of an accident with the help of the timetable. Yang Jingting fell in love with him when she grew up. He wanted to marry her, but she refused. He was devastated when he learned the truth. Yang Jingting finally died of murder. What happened< Br> third party: if you want to save others, but you can't do anything, you can only watch others fall into danger - in real life, whose third party will you be?