The Wanderers - Unicorn Western, #2

Gunslinger Clint Gulliver has been pursuing the dark rider Dharma Kold for over two years, always following but never able to close the distance enough to rescue Mai - the woman that Kold stole from Clint as he left the town of Solace. But now, Clint's hand is forced when his own unicorn companion, Edward, makes a disturbing discovery about the torture to which Clint's almost-bride is being subjected by Kold's unicorn of a different color. Clint and Edward must overtake Kold and put an end to his blasphemy and his quest to reach The Realm before he reaches the Edge - a shifting, disintegrating zone of leaking magic and delirium at the very limit of the world.
But before they can approach, they encounter a new, twisted foe that commands an unspeakable and ancient form of dark magic spewed from the world's very core.