The Sixth Watch (Night Watch, Bk. 6)

Higher Light Magician Anton is one of the Others, possessed of magical powers and able to enter the Twilight, a shadowy world parallel to our own. Each Other must swear allegiance to one side: either the Light, or the Dark. But who is after Anton and what do they want? Anton’s investigation leads him to a Prophet, an Other with the gift of seeing the future. Her horrifying vision heralds the end of all life at the hands of an ancient threat – unless Anton can reunite a mysterious organisation known only as the Sixth Watch, before it’s too late.