Behold a black horse upon whom... a burden of scales.Standing on the brink of ruin, Katherine is uncertain what the fates have in store for her now. With her life on Earth torn asunder by the absence of her friend and business partner, all she can do is watch aimlessly as her friends fulfill their lives, their hopes, and their dreams. Hoping to find some semblance of purpose in her existence, Katherine withdrawals to the one place she feels she can find answers, Wales. But when Baldr, their missing Sun God, kidnaps and entreats her to care for his friend, a wounded hellhound, Katherine decides that for once in her life, it is time to make a selfish decision...He never expected to meet a God, let alone fight a group of them. After the battle between Bianca, the Horseman of Conquest, and Hel, the Goddess of the Underworld, Arwan escapes home to the Welsh coast. If he is to die, then he intends to do so on his own land. But when Baldr is shown a revelation through dreams that ignites the Horseman to remove the remaining hounds loyal to Hel, Katherine discovers that there may be much more to the story than meets the eye.With Hel dead, there should be nothing standing in the way of the four horsemen's victory by stalling Ragnarok. But nothing could have prepared them to face the fact that, like it or not, Ragnarok is coming... coming at the hands of Arwan himself if he dies.Can Katherine go against her friends to save a man she promised to protect? Even if Arwan could end the Horseman for good?On a Black Horse is an exciting third in a series from New York Times and USA Today bestselling author Monica Corwin, if you like the work of Larissa Ione, Karen Marie Moning and Kresley Cole you will love the third book in the Revelations series!