Maddie Fynn is a shy high school junior, cursed with an eerie intuitive ability: she sees a series of unique digits hovering above the foreheads of each person she encounters. Her earliest memories are marked by these numbers, but it takes her father's premature death for Maddie and her family to realize that these mysterious digits are actually deathdates, and just like birthdays, everyone has one.

Forced by her alcoholic mother to use her ability to make extra money, Maddie identifies the quickly approaching deathdate of one client's young son, but because her ability only allows her to see the when and not the how, she's unable to offer any more insight. When the boy goes missing on that exact date, law enforcement turns to Maddie.

Soon, Maddie is entangled in a homicide investigation, and more young people disappear and are later found murdered. A suspect for the investigation, a target for the murderer, and attracting the attentions of a mysterious young admirer who may be connected to it all, Maddie's whole existence is about to be turned upside down. Can she right things before it's too late?