Walkthroughs for Campaigns and Maps in WoGA.

Help!!! I'm stuck!!! Mission #2... the campaign in the lower right corner... is it the 4th one? I captured the castle and destroyed it. I created an undead army. Then, somehow, I managed to pass through the blue garrison, even though I didn't visit any tents. Currently, I need to visit the red keymaster's tent to free the Necromancer Isru. The path to the tent leads through teleporters. But the first teleporter is on an island and is guarded by crossbowmen. But how do I get to the island?? I've run around everywhere. I've talked to everyone... nothing works!!!!!!!!!!!!!!!!!!! The enemy either knows a flying spell or has some kind of artifact, but I can't kill him to try to take it. As soon as it's his turn, he runs away!!!!! What should I do?????? Help!