Wick Chronicles The Emperor of San Francisco, Book 1, (Paperback)

Pacifica 2415
As told by Wick, Royal Cat, House of Blackshear

On a plaza at the edge of downtown San Francisco, Finn--arriving with a broken down, burned out egg-shaped ship--steps out of a time portal and is found by teen royals Oz and Drew. With no memory of who or from which When he is, Finn becomes a puzzle that time-traveler Oz wants to solve, with the help of Drew, a cat named Wick, and the extremely touch-phobic Emperor.

As they come closer to the answers Finn needs, Oz realizes that the question isn't who Finn might be and When he's from, but it's about who the Emperor is--he saved her father's life when he was a boy, but no one knows where he came from, or why he refuses to touch or be touched.

Oz has described him as an icon of the city and protector of all, but now she wonders: where did he come from, and who is the Emperor, really?