Karen Mahoney 
Stone Demon [EPUB ebook] 

The stunning conclusion to the international mega-hit series.The just-unleashed demon hordes have delivered an impossible ultimatum to the Order of the Crow: produce the Philosopher’s Stone, or suffer a reaper storm of demonic tribulation. If alchemist’s apprentice Donna Underwood can’t recreate the mythical artifact, the world will be plunged into a devastating modern-day Dark Age. Putting her dangerously unpredictable powers against a vengeful demon king, two maleficent faery queens, and an immortal magus with his own shadowy agenda, Donna must be willing to make the ultimate sacrifice-but this time, even death may not be enough.