All you can do is open the back way to the cell in the dungeon, by throwing the switch. You can get in the "back way" through Mordred's underground lab.
(see related question)
You have to push it open.
You can't.
Shoot them to break them up, and dodge the pieces. You only have a limited amount of energy for the shields. Get to the giant asteroid (X-11 Y-84) and land there.
in the royal library in the non-fiction section, it will give you a part to click on. this will lead you into the dungeon
The wall in Mordred's underground lab is made of DIRT not rock, and with a little effort you can push right through it. The tunnel leads to the back entrance to the castle dungeon. (You should have already opened the gate when you threw the switch and got the cheese.) (see related question)
You just aim and click. The only time it is effective is when it goes into the dragon's mouth when there are no flames there (you have to put it to sleep for a second or two). Climb around the back, dodge the spike ball, and pull the lever. (see related question)
they aet lunch!
you have to find mordreds secret room(in between the hay barrels) and push on the dirt wall it will break. go into the tunnel and click on the open hole and you will be in the room that you were in before(thet the guards are guarding.
You don't saw it you feed the owl the mouse so he follows you. Then you go to Mordred's hideout and press through the wall after a few secs it will break. Go in the hole with the owl then the ailein will self destruct then you send Merlin (the owl) in between the bars and he'll get the fuel bar (the thing with the green stuff.)
Knights templar
Eventually it would break through the surface of the ocean and then form an island.
above the parking break in a blavk box