Wraithblade

Revi is an assassin on her first assignment-and she's not willing to kill a child. When she goes on the run from her assassin brotherhood with a knife that opens doors between worlds, she runs afoul of three factions: inter-world police, the other assassins, and a shrewd bounty hunter named Jacob Argent. And he's the only one interested in keeping her alive. Now unwillingly allied with Jake, Revi flees across the war-torn world of Tyrona. Against a backdrop of warring factions on floating continents battling via zeppelins, robot suits, and flying monsters, she tries to survive being both pawn and prize in a cosmic chess game between two mega-chronomancers. But worst of all, she's developing feelings for Jake-her enemy. Jacob Argent is a lonely bounty hunter on an assignment-locate the missing person known as Revenant. But when he locates her, he must protect her from the assassins and police-and the growing attraction of his own heart. Now Jake must work through his grief over his dead fiance, before Revi is lost to him forever. Because his actions have earned him the personal hatred of a super-mage called the Oracle, who means to kill Jake any way he can.