Catherine Fisher 
Starspill [EPUB ebook] 

It’s been 140 years since the Wolf swallowed the Sun, so why are all the cats in the dark, fog-shrouded town of Starspill bothering Zac about it now? He just wants to stay warm, listen to stories, and work hard for his brother as an apprentice starsmith. But the cats have other ideas. They want Zac to steal one of the three legendary Embers of the Sun from the town museum for them, and they’ve taken his precious secret map to make sure he’ll agree!