Years ago, boundary witch Allison "Lex" Luther made a promise to an alpha werewolf. Now, just when the supernatural community in Colorado is enjoying a period of hard-won peace, the alpha turns up at Lex's door to call in his marker. Two of his pack members have disappeared in the Colorado sand dunes, and he needs safe passage to hunt for them.

With her friend Simon Pellar along for backup, Lex ventures into the dunes to search for the missing couple...but what they find is only the opening move in an ambitious assault against those who hold power in the Colorado Old World. An old enemy has returned to tear their peace apart, and Lex is soon embroiled in politics she doesn't understand, from a time before she had magic.

To save her friends and her way of life, Lex will have to cross every line she's drawn since learning what she is - and it may still be too late.