Unraveling (Unraveling, #1)

Sixteen-year-old Janelle Tenner is used to having a lot of responsibility. She balances working as a lifeguard in San Diego with an intense academic schedule. Janelle's mother is bipolar, and her dad is a workaholic FBI agent, which means Janelle also has to look out for her younger brother, Jared.

And that was before she died... and is brought back to life by Ben Michaels, a mysterious, alluring loner from her high school. When she discovers a strange clock that seems to be counting down to the earth's destruction, Janelle learns she has twenty-four days to figure out how to stop the clock and save the planet.