2019: Deeply scarred by a difficult childhood, Sara Sullivan prefers the company of her cat to other people - until she wakes 30 years in the past, the only person who can stop a deadly campus bombing.
1989: Charlie Anderson is a lonely outcast who develops complicated feelings for Sara and has a run of bad luck with the campus bully - which together put him on a path to revenge that threatens dozens of lives.
Sara and Charlie gradually find themselves on a collision course toward a horrific event that will rock a sleepy Midwestern city to its core and leave a legacy of death and destruction. As Sara learns that connecting with people is the key to preventing the tragedy, will she be able save the people who have taught her to finally trust? Or will she fall victim to tragedy in the past, forever altering the future?