The Silver Dream by Neil Gaiman

An InterWorld Novel

In a universe where time travel is possible, a young adventurer named Joey Harker discovers that he is a Walker, someone with the rare ability to navigate between alternate realities. As he hones his skills, Joey becomes embroiled in a cosmic conflict involving the mysterious InterWorld organization, which strives to maintain balance across dimensions. When a new threat emerges, Joey must confront the challenges of leadership and the complexities of his own identity, all while navigating a web of intrigue and danger that spans the multiverse.