Game Changer
(Book)

After an especially rough tackle on the football field, Ash thinks he might be suffering some permanent damage, because suddenly stop signs are blue and always have been. After the second universe-altering hit, he drives a Beemer instead of a Dodge, and a pair of interdimensional twins promises him answers. The more universes he visits, the more Ash has to face perspectives he never thought to consider before, and the closer the universe gets to complete annihilation. There must be a way to fix everything, but can he really trust the only people who seem to understand what's going on?