Save the Future You

My wife was terminally ill, so I developed a time travel machine and traveled to the future just to save her. But in the future, my most proud student picked up a butcher knife and killed his wife. In confusion, pain and despair, I searched for the cause of everything. It turns out that the student's mother was also in a dilemma of life and death, and his obsession with her made him go astray. How can I save my student before he turns into a demon? In the journey of extending my wife's hope for life, where is my salvation? This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.