Am I an idiot?

Just started this up from Matras, and I am getting nowhere! I mean, first, I can't get around in the tunnels across to the other side of the tunnel, and the teleport takes me to the asteroid mage that does nothing for me, other than return me to Matras. Can't find the key to open the gate out of the asteroid mage domain, so I have nowhere to go. Any suggestions?

Which tunnels are you in? There is a level called Tunnel and one called Wind Tunnel.

What level is the "Asteroid Mage Domain" called? Is that "The Alternate Dimension"?

I need more information in order to help you especially as this is a very old expansion.