33 Degrees

You haven't arrived, until you're departed.
Seventeen-year-old Gwendolyn O'Karran survived a kidnapping. Her best friend Sarah did not-and Gwen has absolutely no recollection of the events that led to Sarah's death. With her life torn to shreds and her heart tormented by survivor's guilt, Gwen doesn't expect much from her future, least of all the boy she's had a crush on for years to attempt suicide-or herself to rescue him. Twice.
But: seventeen-year-old Kai Harrison is convinced he has a valid reason to kill himself. He and his twin brother Cole were in an accident that caused their hearts to stop-enough for Kai to get a first-hand impression of what lies beyond the confines of life. All he wants is to flatline, enter the afterlife, and bring Cole back from the coma he's in.
As crazy as it sounds, Gwen, conscience heavy from Sarah's death, is intrigued. Obsessed about reuniting with their loved ones, Gwen and Kai come up with a plan to flatline themselves and trigger a near-death experience. Their quest to beat death at his own game brings them closer, but when they plunge into their reckless experiments, the boundaries between life and death begin to blur. As disturbing visions begin to haunt Gwen and force her to confront the consequences of trespassing to the other side, she realizes she opened the door in both directions when she pierced the veil of life and death. Everything Gwen thought she knew about the night that killed her best friend is challenged-and the secrets that surround Sarah's death are still very much alive.