Sully has two quests for you- Welcome Wagons, and something extended that pretty much shortens down to ‘Maybe If We Try This?’

Welcome Wagons is relevant to the explosives the Horde have here- huge wagonsful all over the place in their camp.  Sully wonders aloud if perhaps they just intend to blow the continent up rather than take it over.  This is most likely invective, given the tendencies of the Horde to date, though that doesn’t actually rule out -accidentally- blowing up the continent.  Goblin engineering has tendencies like that.  This aside, your job here is clear- take his flaregun, and use it to set the wagons off here and now, before the explosives can be placed to do some real damage.

The other quest, No Plan Survives Contact With the Enemy, is a typical kill-quest.  Apparently SI:7's covert-ops nature really isn’t working well right now: Rell Nightwind snuck into the camp to look for Anduin Wrynn and Admiral Taylor, but he’s gotten pinned down by patrols in a tough spot and you’re needed to cut a hole in the defenders so Rell can be given some help.  Toward that end, you are to kill 6 Garrosh’ar Grunts and 6 Garrosh’ar Gear-Greasers.

Far and away the hardest of these three goals is to kill 6 Gear-Greasers.  The goblins love to cluster up so that it’s virtually impossible to face only one of them at a time.  Most cases, you’ll be fighting two Gear-Greasers simultaneously and occasionally three, an especially injurious prospect.  You’ll want to proceed cautiously as you enter the Horde base because of this.  While the Grunts aren’t too dangerous, being basically Warriors of modest skill, the Gear-Greasers will group up and really ruin your health bar.  Worst is if you manage to get some Gear-Greasers on you and attract a Grunt, because the Grunts’ Thunder Clap will slow your attacks, giving the Gear-Greasers that much longer to murder you.  Just to make things worse, Gear-Greasers hang out around the explosive carts a lot, for reasons that I won’t bother to explain, and so you’re liable to run afoul of them at unexpected moments while preparing your flare gun.

The war wagons are very easy to handle in and of themselves- in the process of heading towards Rell’s current location, you’ll pass exactly five wagons.  Keep your eyes peeled for them- they’re not hard to spot, being giant carts full of obvious barrels and fireworks- just make sure you have your backpack open so you can use the flare gun to set them off.  They also conveniently kill off a few Grunts that stand guard near them, helping to clear your way to Rell.  Rell, incidentally, can be found near the docks, crouched atop a stack of barrels and crates- one of which he has apparently dumped on a nosy peon, crushing the hapless orc.  (And there’s a term you don’t see too often- ‘hapless orc’.)  He appears to be watching the ships at the docks, as well as one particular dock which is blocked off by a large hunk of wood with giant metal spikes protruding from it.