The Barbed Coil — J.V. Jones

A ring that seeks blood instantly transports young Tessa McCamfrey to a realm where pictures and patterns hold vast magics; where a sorcerous crown--the Barbed Coil--can reweave destiny; where a mad king is using the crown to conquer an ancient land. And somehow Tessa, aided by two men whose pasts entwine with her own, must master a pattern of ancient powers before the Barbed Coil ravages the fate of a world...