Warcraft 3 Frozen Throne Walkthrough for Undead Scourge:
Chapter 7 Part 3: Ascent to the Upper Kingdom
Main Quest: Escape the Caverns
Optional Quest: Gold Stashes
Arthas will be all alone for the majority of this mission. You must be mindful of the game clock running down on you as you proceed. There are a number of obstacles here that require timing and planning. The first is just south of where you begin. Time running through the flames with Arthas so that he isn't hit. The next room is even harder, but you shouldn't worry too much as a fountain of health is coming up. Watch for the section in each flame wall that goes on and off, then quickly step on the switch. A few of the times you will need to navigate a turn. Click on the ground where Arthas first needs to go then quickly put the mouse cursor on the switch and click. You will likely take a few hits as you go, but as long as you survive a small interlude at the fountain of health will bring you back to full. Return back to the flame room and hit the switch to the north to fight a small scorpion and get claws of attack +15. The obvious item for me to ditch were the claws of attack +9. If you must choose, choose quickly. Hopefully you kept the spiked collar from an earlier chapter for it will come into play in this very mission.
The next room in line isn't challenging at all. There are far too many runes of healing and mana for you to die here. A death coil can kill a forgotten one in a single hit, so use it liberally. Hit the shield wall power generators when you come to them. The path will coil toward the center. The last forgotten one here will drop a tome of intelligence +2 for Arthas, great! Hit the generator to reveal a phantom bridge which you can cross. Kill the forgotten ones in the next room. Soften up those Arthas isn't already attacking by using death coil. Hopefully you can use your spiked collar here to have the summoned creature step on one of the switches while Arthas steps on the other. You'll get a hood of cunning with +4 to intelligence and agility. Grab the healing potion before you pick this up, if you need to use it. Otherwise skip the potion. Move on to the east.
This room can be frustrating. Work your way east, always. There is a ring of protection +5 here but I could not find a way to recover it, I believe it may even be there as a time sink. If you find a way, drop me an email through my contact form. The first forgotten one to the east will drop a tome of strength to further empower Arthas. Once you make it to the eastern side, Anub'arak will greet you. Follow the path through the caverns to the south. When you reach the first big room, grab the coins hidden in a crate to the south then proceed east. There is an Orb of Darkness to be found here, and the Nerubian Annihilator will drop a crown of kings +5. I chose the crown of kings over a ring of protection +2 for Anub'arak, and ditched another ring of protection +2 for the Orb. Head on through the doorway to the east to finish the mission.