This is the sequel to Legend of the Orange Scepter , a YA novel I reviewed earlier this year. In this one, the rascal hero team struggles to track down the remaning threat from the first novel. But their enemies are very clever and use subterfuge to break up the hero team. Maybe if they weren't more focused on hooking up with each other, they'd get along better... I'm just sayin'
Anyway, like many books in the genre, it follows a similar arc of disssunity and reunity along with past regrets. I'm not saying it follows Age of Ultron in terms of storytelling, but it does have some similiarities. I think it made a solid sequel, even if I didn't like the ending. Readers, y'all know how I feel about family, but the line stops at attempted overthrow.
I think he set the sequel up in such a way that makes a followup a certainty. Whether or not it'll be a conclusion is up in the air. He might go the X-Men route or he might go the Harry Potter route. Your guess is as good as mine. And that's the best part of reviewing; determining whether your gueses are going to come true.