Preppies of the Apocalypse

Preppies of the Apocalypse is a 2014 young adult novel by Morgan Richter.

Still reeling from a devastating tragedy, Kit Garrett struggles to adjust to his fancy new prep school. When his estranged older sister Ivy starts undergoing a frightening physical transformation, Kit embarks upon a quest to save her. He follows Ivy into a cave near his school and finds himself stranded twenty years in the future, after a mysterious catastrophe has obliterated almost all traces of human life.

Accompanied by his nemesis Ashley, the star of the school’s lacrosse team, Kit makes his way across a destroyed land in search of his sister. Defenseless and in way over their heads, Kit and Ashley face off against a succession of dangerous and bizarre creatures: vicious imps with a taste for human flesh, telepathic cockroaches, and a gorgeous but lethal glass dragon. While Ivy struggles to come to terms with her ghastly birthright, Kit unearths the long-buried secrets of his own dark past. Kit’s mission becomes clear: rescue Ivy, find a way back to his own time… and save the world, if he can.

Preppies of the Apocalypse is based on a screenplay Richter originally wrote in 1999. It's also the title of Richter's personal blog.

It's a stand-alone book in that has no ties to any other work in the Luft Books universe.

Major plot spoilers in the below links are blackened out. To read spoilers, simply highlight the blackened words.

Characters in Preppies of the Apocalypse:
Kit Garrett
Ivy Garrett
Ashley Thorne
Valentine Parrish
Apocalypse Ivy
Insane Ivy