luke is the one who changed in the book because jens dad gave him a fake ID so he could live his life and doesnt have to hide from the population police anymore.
The main characters are Luke Garner, a third child, Jennifer Talbot, another third child, (friends with Luke) Matthew and Mark, Lukes brothers and his parents Mr. Tablot, who gives Luke a fake I.D.
Luke Garner - protagonist; Matthew and Mark Garner - Luke's legal brothers; Mr. & Mrs. Garner - Luke's parents; Jen Talbot - foil to Luke; Mr. & Mrs. Talbot - Jen's parents; Carlos - another...