Thrace and the Centaur: The Alcyoneus Bone by Keith Bender

Thrace, exhausted and confused, is rushed home to Colorado by Aphrodite, the Goddess of Love. Reunited with Parker and his mother, Cybele, Aphrodite informs Thrace that he must fulfill the oath he swore to her, to come when called. Thrace and Parker must join Sophos and rescue Ares, the God of War, from his stepbrother, Cresphontes. It is not the quest Thrace expected from the Goddess, especially as he was still haunted by the journey through the Underworld and his time with Styx, the Goddess of Hate. But Thrace of the Spear, the Bringer of Blood, must come to terms with his own choices and actions, and going forward, understand the choices of his father.