The Withering Dawn - The Eternal Embrace, #1

A Heaven, beset by plague and promise of war. One angel hopes to save Heaven; another, to save her friend. The angel Elysia's closest friend Mirelle disappears on the day of the Convergence, leaving Elysia no choice but to believe that she'd been Chosen to rejoin the essence of the long-absent Creator-a bittersweet fate that leaves Elysia grieving and alone on this holy day. But soon after a chance encounter with the enigmatic Alirion, who comforts and encourages her, it becomes clear that Mirelle was sent in haste to the distant city of Vigilis, where a terrifying plague has surfaced that threatens to consume all of Heaven.
Haunted by the thought of Mirelle trapped in plague-stricken Vigilis, Elysia is determined to find out why; but she has no idea how. Yet soon Elysia and Alirion discover that the plague may only be the beginning. Whispers of war new and old, and of a divine conspiracy in the Angelic Council all begin to surface, forcing Elysia to question everything she thought she knew about both Heaven and herself.
Angels can fall, and Heaven's peace is a fragile illusion. Every footfall or wingbeat could save or doom not just her friend, but all of Heaven. For it soon becomes clear that The Withering is more than a disease, and the path to salvation could prove to be paved with sacrifice.