'When mirror twins Seth and Hadrian Castillo travel to Europe on holidays, they don’t expect the end of the world to follow them. Seth’s murder, however, puts exactly that into motion.
'From opposite sides of death, the Castillo twins grapple with a reality neither of them suspected, although it has been encoded in myths and legends for millennia. The Earth we know is just one of many "realms", three of which are inhabited by humans during various stages of their lives. And their afterlives...'
Source: Publisher's blurb.