On Michael's birthday, while Brennan and his mom were decorating the house for his party, he plays catch with his father just outside the woods. Michael chases after the ball into the woods and is transported to Terrenos.
One year later he returns to earth older and is found wandering the woods and taken to the police station for interrogation.
Brennan enters the interrogation room to try and discern one way or another if this was truly his brother. Aaron (their father) recognizes him as his lost son and helps free him the interrogation room. Brennan leads him to where his weapons are stored.
Michael spent years in a land called Terrenos, defeated the evil overlord "God King Lore" and returned to earth chasing residence of Terrenos and agents of God King Lore. Michael's must defeat these agents before they destroy the earth.
The story cuts between present day on Earth and his adventures in Terrenos. Upon arriving at Terrenos he is discovered by Gideons called Ansari, Shavo and Rya. They take him to meet Rook who reveals that Michael is destined to be Terrenos's champion and free it's people from God King Lore's control.
In a twist, it is revealed that Michael is actually possessed by God King Lore and a has returned to Earth a his agent.