Rebecca Yarros recently revealed the back cover of Onyx Storm, and the sneak peek at the upcoming Fourth Wing sequel makes the wait for its release slightly less agonizing. Readers sometimes wait years for new fantasy books, so the 15-month break between Iron Flame and Onyx Storm isn’t terrible by comparison. However, Iron Flame‘s cliffhanger ending is enough to make even a shorter wait feel excruciating. After all, the final moments of the book put both its male lead and its central romance in jeopardy.