The Alchemical Lab is a short, peaceful, yet complex mini-dungeon located at the back of the slums in Sirus. One can find the entrance by following the water stream in the slums all the way to its source. The dungeon revolves entirely around a unique puzzle mechanic in which the player runs between various crafting stations, trying to make ingredients for a potion. This potion is the Acid Vial legendary, which is both a useful tool in its own right and a prerequesite to acquire the Sirus Emerald Shard for the Emerald Quest. The Acid Vial is the only obtainable item here - there are no chests. If you do not need one, coming here is a wasted trip.