The Hourglass Door (Hourglass Door, #1)

His past. Her future. Can love bring them together in time?
Abby's senior year of high school is textbook perfect, until she meets Dante Alexander, a foreign-exchange student from Italy. Time behaves differently when they are together - too fast or slow or seeming to stop.

When the band Zero Hour performs at the local hangout, they have a bizarre influence over their audience, and Abby's best friend, Valerie, is caught in their snare. Dante helped Leonardo Da Vinci build a time machine, then was sent 500+ years into the future as punishment when falsely accused of being a traitor. As past and present collide, Abby learns she holds a special power over time itself.