Devil's Icebox is book two in the Dark Earth series.
Lord Baxter’s portal between Earth and Dark Earth beckons. Eager to seek the promises of the otherworld’s powers, Cassiopeia has been sent by her Lord to ensure his realm rivals the mightiest of nations.
She shares a history with the protector assigned to her, a history filled with familiarity and contempt. Setting the past aside and sharing the present offers forbidden opportunities, as well as a new world filled with opportunity and unimaginable surprises. Her quest remains the only constant, and the one thing she yearns most to be rid of.
Look for these other Dark Earth books:
Dark Earth
Devil's Icebox
Soulmates
Voices
Bound
also The Lost Girls series