Tusks. Just Cause Universe, #9

Make a deal with the devil. A few years ago, Mustang Sally had to make a deal with her worst enemy in the entire world: Destroyer, the man who killed her father. He agreed to use his technology to reverse a nanotech plague and save the world. His price? A favor, to be collected from Sally at some point in the future. Give the devil his due. The time has come for Sally to fulfill her obligation. Destroyer needs her to help him save the life of his sister, who has been trapped in a comatose state for nearly her entire life.
Sally will have to enter the woman's Dream-world, with help from her teammate Minerva and Destroyer's nephew March. Once there, she must complete an epic journey through the woman's mind and find the key to unlock her consciousness and release her from her coma. She quickly discovers things that can harm her in the Dream-world have dire consequences in the real world, and Sally must swallow her pride to fight for a life precious to the man who stole a life precious to her.