Every May 1st, a serial killer stalks a small town. Every year he comes for them . . .

On May 1, 1992, Jules Delaney and Quinn Riley hardly know each other.

Jules is high school queen bee in a small Midwestern town when she survives a brutal attack by the elusive May Day Killer - a predator who strikes every May 1st and then vanishes without a trace. Quinn, a boy from the wrong side of the tracks, is arrested the same night after trying to break up a fight and nearly killing someone.

By morning, their lives are forever connected.

A year later, Jules is haunted by trauma and guilt, tormented by one question: Why was she spared? Quinn is newly released from juvenile detention and returns home to devastating news - the unsolved murder of his mother.

Over the next decade, their lives are revisited on a single day each year: May 1st.

As the years pass, secrets surface, lies unravel, and the paths of Jules and Quinn draw closer together. Two mysteries edge toward the truth - what really happened the night Jules was attacked, and who murdered Quinn's mother? All the while, the May Day Killer is still out there.

And the clock is racing toward another anniversary.