A Necklace of Water — Cate Tiernan

The Balefire coven has tried and failed to replicate the original rite that bestowed immortality upon them centuries ago. Some were hoping to finally die, others to discover new reaches of power. Twins Clio and Thais weren't sure what to expect, but now they are forced to confront a hidden enemy who still wants them dead. In addition, they're coping with the love they both feel for the same person, who has finally made his choice.

Readers who devoured the first three books in this thrill-ride series will be dying to see what happens next, and they'll be rewarded with a shocking turn of events that no one will predict!