Morgan Stockhour knows getting too close to the edge of Internment, the floating city in the clouds where she lives, can lead to madness. Even though her older brother, Lex, was a Jumper, Morgan vows never to end up like him. If she ever wonders about the ground, and why it is forbidden, she takes solace in her best friend, Pen, and in Basil, the boy she’s engaged to marry. Then a murder, …