John Rayburn was angry.  He'd gotten in trouble at school for beating up a younger student.  He told the boy's mother what he thought of her and her son.  She'd called his parents and the principal.  Now, he was in real trouble and he didn't know what was going to happen.  Thus, when he saw someone in the woods, he was already on edge.

The young man claimed to be John Rayburn from a parallel universe.  He offered to take John's place in the home and school while John took a trip to the next universe.  John Prime, as the first traveler called himself, showed his twin how to use the device.  John still wasn't convinced Prime was telling the truth.  Nor was he sure Prime could take his place.  But when the principal told him he had to write a letter of apology to the woman he'd offended, he decided to try it.

He took the cash Prime gave him and set the counter to universe 7534, one more than the 7533 of his own.  Then, he pulled the lever and shifted.  Things looked so much the same, he wasn't sure anything had happened.  But when he went into the Findlay, Ohio, library, his research showed the differences Prime said he'd find.  So, he set the counter to 7533 and pulled the lever.  Nothing happened, even after more than twelve hours of recharging.  Prime had lied.  He couldn't go home.

The Walls of the Universe is a tale well written.  The characters are richly developed, fully human, except for the nonhuman aliens.  For John, Prime had pulled the ultimate identity theft.  The ensuing adventures give one pause when considering travel between universes.  The story is intriguing enough I didn't want to put it down.  Since this is only Melko's second novel, he's a writer to watch.  See for yourselves.