In 1916, Emma O'Neill is frozen in time. After sampling an experimental polio vaccine brewed on a remote island off St. Augustine, Florida, she and her family stop aging, as do the Ryans, her family's business partners. In a way this suits Emma fine, because she's in love with Charlie Ryan. Being 17 forever with him is a dream. But soon a group of religious fanatics, the Church of Light, takes note. Drinking the elixir has made the O'Neills and Ryans impervious to aging, but not to murder.
Fourteen-year-old Jenna Samuels is having a very bad eighth-grade year. Her mother spends all day in bed, her father has vanished, and her 16-year-old brother Casey tries to hold the family together. And Jenna is sick. When she collapses one day, Casey crashes driving her to the hospital. Jenna wakes up in the ER to find Casey beside her. But Casey didn’t survive the accident at all. Casey has been sent back to help solve the mystery that not only holds the key to her survival, but also to their mother’s mysterious depression and father’s disappearance
It's been almost a year since Jenna Samuels' stoner brother, Casey, bit the dust and returned as her guardian angel; a year since Casey and his "angel boss", Amber Velasco, saved Jenna's life and helped her foil the bad guys, more or less; a year in which Jenna has solved the true mystery of the universe: how to get one Ryan Sloboda to ask her out.