Right, the box!
What was wrong with his brain? Why would he obediently get into the box as instructed?
He felt that he was not playing with his full deck of cards.
There was no way he was going to perform on stage later, and since he was planning to escape, why would he be cooperating with the magician?
He was probably too distracted by the gathering of the mages that he totally forgot about escaping.
There was no point for him to stay since he had identified the mages in the theater. He did not intend to leap out of the box, enthusiastically take Henry into an embrace and shout, "Oh, my lad, I’m a mage too!", which could lead the thirty over mages backstage to break into a group hug and sob dramatically. No. Definitely not that.
The initial curiosity died down too.
So what was he still doing here?
He should flee!
Benjamin immediately started plotting his escape from the theater.