Thrills! Chills! Betrayals and sacrifices! Who ya' gonna call? Gravion! The Gran Knights are back with an interesting assignment: To patrol an amusement park! While it may be a fun time, it doesn't last. There is an abundance of Zeravire lurking around. Then, one of our heroes has a shocking epiphany and finds out about her past - the hard way. The Gravion team is in total disarray. Two of the Gran Knights turn up missing and one has fallen into a deep coma. And, there seems to be no promise of improvement. Even Sandman seems to be on the edge of a breakdown. He's discovered who is behind the Zeravire attacks, and it isn't a pretty picture. All we can hope for is that the team can overcome all the challenges that are associated with protecting the Earth. Find out which Gran Knight betrays the rest, who gets captured, who reveals a true identity, and which Gran Knight will offer up the ultimate sacrifice in this nail-biting volume of Gravion Zwei!