I tried the loot cave for the first time tonight. It was ok loot but so boring I was about to quit. Then the announcement came that the Hive and Fallen were starting to fight or whatever. A second cave opened up right next to where 6 level 25+'s were farming. From this cave came a non stop barrage of Hive, and then from behind came a shit ton of Fallen. We had 2 Titan strikers, 2 void walkers and 2 sin singers. Too bad no arcblades. But the strikers and voidwalkers were generating enough orbs that the sun singers kept radiance up full time for like 5 minutes. Everyone just spamming grenades left and right and supers all over everything. When it finally ended there were engrams EVERYWHERE! Most fun I have had in the game yet. It lasts about 4-5 minutes in total I think. Way better than a warsat.