|Complete Bright Lights, Flying City||18||Caustic Caverns||3208 XP, 4 Eridium|
There will be a post in the Caustic Caverns that has an ECHO recorder on it, which is where you will start this mission. Your job in this mission is to escort a mincart through the caverns, but when you get to it, you find out that you have to actually push it. One of the easier ways to do this is to turn your back to the cart and push it that way, as this allows you to concentrate on any enemies that rear their ugly heads.
Along the way for the first section, there will be a few Crystalisks. Eventually, you will reach a locked gate that must be opened, but clear out all of the enemies first before you go to open it; you'll find the switch in the little alcove. You'll need to open two more doors until you get to the grinder, with threshers and varkids along the way. Push the cart onto the belt and activate the grinder, then simply go have some fun with the local wildlife until it's finished. Grab the raw eridium and turn in the mission.