Happenstance: Book 5 of the Spellbound Railway Series

On the run from the killers who took their best friend from them, spellcasters Kean and Robert are trying to stay alive in the dying reality they are trapped in. But the crisis goes far beyond one reality: the Probability Spine that binds all the realities together is about to break, and if it does everything will end. They must escape and find a way to restore the balance and save all existence.