Hush: Book Two of the Dragon Apocalypse

The invulnerable, super-strong warrior Infidel has a secret: she's lost her magical powers right at the moment when she needs them most. To keep a promise to a fallen friend, she must journey to the frozen wastelands of the north. Her quest leads her through the abstract realms of the Sea of Wine, where she uncovers a conspiracy that threatens all life. Hush, the primal dragon of cold, has formed an alliance with the ghost of a vengeful witch to murder Glorious, the dragon of the sun, plunging the world into an unending winter night.
Without her magical strength, can Infidel possibly survive her battle with Hush? If she fails to save Glorious, will the world see another morning?