World Walkers

In Neal Asher's standalone novel World Walkers, Ottanger, a rebel and mutant living under a brutal regime on Earth, discovers he can travel between alternate universes after an experiment on him goes awry. As he explores the multiverse, he encounters allies like the evolved human Fenris and faces looming threats from powerful forces seeking world-walking technology. With war on the horizon, Ottanger and his companions must navigate conflict and seek to prevent the unstoppable rise of the oppressive regime.