The Gates Of Winter( Series - Last Rune )

In a masterwork of brilliant storytelling, the epic fantasy of two parallel worlds--mystical Eldh and modern Earth--takes a surprising turn in Book Five of Mark Anthony's thrilling saga of magic, suspense, and adventure," The Last Rune."
The Gates of Winter
The enigmatic Shemal has known only two Runebreakers. One, her rival Kelephon, served the Pale King and his army of apocalypse. The other was Travis Wilder, the Runebreaker of prophecy.Now, in outcast and newly made Runebreaker Larad, Shemal has found a weapon to open the door between worlds. As the shadow of Shemal's master, the vengeful god Mohg, Lord of Nightfall, looms, Grace Beckett seeks to harness wild magic and Travis Wilder joins her in the struggle between warriors and mages, witches
and kings and betrayers of every form.
As the time of final reckoning approaches, Travis and Grace will find themselves facing a dark conspiracy of evil whose virulence threatens to overwhelm anyone who stands in its way. Yet if they don't succeed in stopping it, two worlds will be lost forever.