Broken Skulls Pass

You and your fellow heroes wait anxiously in one of the many outposts established by the great Rogar in the resistance against Zargon’s advance. The door opens, and Rogar himself enters. “Welcome, friends. I am glad you could assist on this, it is a mission of great importance. The Soul Gem, an ancient Chaos artifact, is being delivered to Zargon. Rumors are that it could turn the tide in the Black Banner’s favor. You must stop it. Your mission is to ambush their supply line in the Pass of Broken Skulls.  A regiment has already advanced there and taken out their sentries. Steal the gem and escape to make sure it does not make it through to the front lines!”

This quest requires only the base game and the Kellar's Keep quest pack, and possibly the Frozen Horror if you want to use the ice tiles for the ice wall trap.  Otherwise you can use proxy tiles from the base game.