Yeah, it's a short hike. And you don't have to do it at all, if you don't mind missing out on 20k xp -- just take the key that dropped in Samuel's lair, go north from the gong entrance, use the key, and off to act 2 for you.
It's worth getting the coal for another reason: Taking off the stupid Citadel armor and murdering everybody for the xp and loot. <img src="/ubbthreads/images/graemlins/evilgrin1.gif" alt="" />