Thrice Bound (Greek Myths #5)

When Hekate's tyrannical father - a powerful mage - makes one demand too many, Hekate flees to the Caves of the Dead, where her father's magic cannot reach. But the Caves are protected by a spell of terror and revulsion. To remain there without going mad, Hekate reluctantly takes on a second binding - to the Caves themselves - which will kill her if she fails to satisfy the forces that rule them. Hekate cannot loosen her new bonds until she completely escapes her father's baleful influence. But when she learns that her more-than friend in the Caves is cursed, never to be able to escape, Hekate willingly becomes thrice bound to free him.