The Third Rule of Time Travel

Scientist Beth Darlow has discovered the unimaginable. She's built a machine that allows human consciousness to travel through time—to any point in the traveler's lifetime—and relive moments of their life. An impossible breakthrough, but it's not perfect: the traveler has no way to interact with the past. They can only observe.
 
After Beth's husband, Colson, the co-creator of the machine, dies in a tragic car accident, Beth is left to raise Isabella—their only daughter—and continue the work they started. Mired in grief and threatened by her ruthless CEO, Beth pushes herself to the limit to prove the value of her technology.
 
Then the impossible happens. Simply viewing personal history should not alter the present, but with each new observation she makes, her own timeline begins to warp.
 
As her reality constantly shifts, Beth must solve the puzzles of her past, even if it means forsaking her future.