The Night She Disappeared by April Henry

Gabie drives a Mini Cooper.  She also delivers pizzas part-time.  One night, Kayla, another delivery girl at Pete's Pizza, goes out with an order and never comes back.  To Gabie's horror, she learned that the man who called in the fake pizza order had asked if the girl in the Mini Cooper was working that night.  Was Kayla's fate really meant for Gabie?  Obsessed with finding Kayla, Gabie teams up with Drew, who also works at Pete's.  Together they set out to prove Kayla isn't dead, and to find her before she is.

Another fantastic thriller by April Henry.  Fast paced and intense read!

Stolen by Lucy Christopher

While sitting in the airport with her parents, sixteen-year-old Gemma strikes up a conversation with Ty, a gorgeous young stranger. Before she knows it, she is drugged by Ty and dragged off to the Australian outback where she is held captive. Soon Gemma realizes this desert is so desolate and remote that any escape attempts are futile. In time she believe that Ty is not as despicable as she first believed. But, is she just tired of fighting and willing to give up or will this nightmare eventually come to an end. One thing she knows is that she is losing hope as each day passes.