Hmm, in the secret room 19 ( I think ) there's a gate with the same patern that has in some Ancient Temples, so I tought that Gravitron or Norman could open. But ''How to fix Gravitron before the Orc Fortress be destroyed?'' and ''How to make Norman join the party early'' It's impossible, so I tought in a way of not blowing up the Fortress, and I did it. XD I spent all my dynamites in that gate and now that Marine don't have dynamites she can't blow up the Fortress, isn't that wonderfull? Aha Indy, good one, but not good enough for me.
Don't know if anyone discovered this already, but well... I posted anyway.