The Alchemists of Loom (Loom Saga, #1)

by Elise Kova

Before the first Fenthri broke through the clouds, the Dragons had called the seemingly impenetrable barrier the Gods’ Line, as it separated their world from the next. Boco, the bird-like creatures they used to fly between the islands of Nova, lost control of their wings as they neared the speeding winds that always wove through the clouds. Every Dragon who tried to descend on the back of a Boco fell violently through the line and was never seen again. Certain death by falling into the afterlife had made attempts to descend unappealing. And for hundreds of years, no Dragons tried. When the Fenthri barely broke through the clouds, only to be shortly torn asunder by the winds themselves, Nova learned that it was not the afterlife on the other side of the line but another world entirely. Curious Dragons—fools—attempted to cross once more at the site of the first breach, but fell to their deaths. It was their corpses that provided the organs that led to the first Chimera being pieced together by the Alchemists.

Good worldbuilding