A planet divided. Two enemies with everything to lose. An alliance that could change the fate of their world forever. No one knows how the Gap that stretches across planet Naisyle came to be, or why life on either side is so drastically different. For as long as ASTRAEA ELMS has known, the Outers on the city side of the Gap have been hunting and kidnapping the people of Arden Village. She has been training since childhood as a Sentinel, and when the unthinkable happens, nothing will stand in her way of protecting her people. JAS MARECELLO has been hidden away in the Zenith building in Syong City since he was ten years old. Hostilities by the Gappers, those living on the village side of the Gap, have made it too dangerous for him to leave the tower building. But when he meets a Gapper that invades the Zenith building, he can't tear his heart or mind away. Together, the two must unravel the truth about what is happening in the Gap and the cause of the growing animosity between their people. But the answers they find are far more sinister than either could have imagined.