I think this is a question regarding FFXII: Revenant Wings.

I haven't played the game, so don't really understand it at all, and I haven't found any guides that deal with this situation, so I'm not sure how accurate my information is. Are you certain there is a Summoning Gate in the level you're on?

That's about as much advice as I can draw from an internet search. Hopefully there's someone in the FFXII forum that has a better understanding of the mechanics.

EDIT: It appears I spent over 40 minutes searching for information and never came across that post.