Love in Time Prison

Ava Summers has an emotional deficiency and does not feel fear the way other people do. She is caught in a time loop that resets. Each cycle ends in the same tragedy, and at that end point she works out that all of it is tied to Matthew Foster, a classmate she used to have feelings for and never told. Because fear does not reach her, she moves through the repeats calmly and takes the thing apart a layer at a time. The killer turns out to have had long-standing ties to both her and Matthew, going back years. What is behind it is an obsession buried in the past. She has to get out from under the ending she keeps arriving at, find Matthew a way to live through it, and stop the loop for herself.