Go Back in Time

What can we do when we go back to high school? Am I not the only one who can go back to the past due to emergencies happening one after another? Some people's personalities have changed in high school. Why? The butterfly effect is still time travel, it doesn't matter, making money is the way to go! But with the occurrence of several murders, I realized that things are not that simple and what should I do? This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.