The Locket Chronicles ─ Bok

Ireland, 1014 AD, was a turbulent time; but wing walkers Kate Phillips and Jen Fillmore discover that the fate of the island is tied to an island in another world-Gudsrika Isle in the world of Bigna. Caught in a world between medieval mercenaries and twenty-first century cell phones, Kate and Jen find their lives hurled into a sinister domain of deceit, treachery and tomblike dungeons. Brought to Gudsrika Isle to prevent the magic of the BOK, the sacred writings of Gudsrika, falling into the sorcery powers of wicked Queen Ionta, they must trust the supernatural power within their lockets to save them from being imprisoned for eternity by Rapio--the dark, mystical leader of Gudsrika.
BOK, the first book in The Locket Chronicles, is a continuation of the lives of two characters, Kate and Jen, in the first series by Carole Bailey, The Morgan Chronicles.