It all starts with a keg of beer.
Actually, let's do full disclosure here - it was a few kegs. Several, actually. Blue Dragon Ale, the trademark brew of some small time brewers living in the woods near Neverwinter, is packed and ready to go to town and be sold. Yet the Brewers, as they are known, have plans for this haul's profit.
The Brewers have but a small shack where they brew their ale in the solitude of the forest. Many are outcasts among polite society, being born of strange blood. They have made peace with the forest, and are at home there, brewing their ale and living off the land. The Dragonlord Bahamut is their patron, and they have built a small shrine nearby. However, with the way darkness encroaches upon the land, it is clear something must be done to preserve their way of life.
Now, Mehmet / Betsy is tired of sub-par ingredients for their brew. The first step, he insists, is that they make better beer. With the money from this haul of Blue Dragon Ale, they can go to Neverwinter and find better hops and barley for the brew. Once they have the best brew on the Sword Coast, the Brewers won't have to worry about the safety of their home and way of life amidst the chaos that embroils the region.
In order to make some more cash, the group agrees to travel to Phandalin with some other wares. The wagon is loaded down, and the Brewers begin the first leg of their journey. It doesn't take long before trouble begins.
A group of goblin bandits ambush the caravan, but the Brewers chase them back to their hidden lair. The goblins are defeated and scattered, and the characters begin to look around. Ahead of them is a goblin's cave...but the wagon is left unguarded. After a short argument over what was more important, the Brewers prepare to enter the goblin warren...