Witchlight (The Witchlands, #5)

Paths converge and prophecies unfold as Safi and Iseult―the legendary Cahr Awen―fight their way across the Witchlands to heal the final Origin Well. With ancient figures rising from the past, the Raider King’s armies gathering for war, and the magic at the heart of everything dying too fast, the entire world is now on the brink of collapse.

But when Safi and Iseult reach the Air Well with the Bloodwitch Aeduan at their side, they discover too late that Eridysi's Lament is not the prophecy they thought it was―and their journeys are only just beginning.