Alright, first of all start up by getting more gold at the other mine. I suggest u begin to research right away, since then when u have troops your upkeep goes higher, and you don't get so much money. After u have that done, start building up a defense. make moon wells at the front of your base, and the ancient protectors behind them. the computer is sometimes dumb, and the enemies just run around at the front of the moon wells, and the eventually die. After the defense, start making people. I suggest archers (fully upgraded) and druid of the claws. (research bear form) when your allies call for assistance, don't waste your guys. send your heroes, and when the begin to die, use a special power and get out of there. if you want to, go to the mercenaries and get those free people, the bad part is that they take up food, so don't buy too many. the key part in this mission is to stall as long as you can. if that defense doesn't work out, (the lich king unusually puts death and decay on it) spread your guys out, and that splash damage is ineffective. if the lich does do death and decay, but u still win the battle, immediacy start building again, but the lich will return, so spared your acn. protectors out. Hippogriff with riders also work well here too.