The Lost Expert by Hal Niedzviecki
When Chris, an unambitious young waiter, walks through the park on his way home from work, he stumbles onto the set of a Hollywood film―and is promptly mistaken for the missing lead actor. Corralled into filming a scene, Chris assumes the identity of the actor and disconnects from his real life. He falls deeply into his newfound identity and must grapple with his role as imposter and whether he can―or even should―extricate himself from reinvention.
