During the final fight with Crota, once the team starts fighting the swordbarers, one of the blue gatekeepers you had to kill with the sword to pass the bridge spawns above the Crystal summoning room. (It appears one spawns with each sword drop)(If you jump high enough from one of the pillars he is visable. He has also on occation walked all the way forward to the railing.) So far, we have speculated that there is an area only openable (possibly by the sword carrier) after killing this gatekeeper with the sword, that should contain the 3rd chest. Edit: It is now understood how to get up to the gatekeepers. There are two ways so far. Jumping along the rocks from where crota spawns around the top and dropping down. Or, with a titans booster jump, from the top of the yellow pillar lamp you can jump over the invisible barrier. Several ideas as to how to get there include: - jumping up with sword in hand (perhaps working like a barrier key like walking on the bridge.) - does not work. -It may be a timed trigger for when the barrier drops or this area becomes accessable/unaccessable before, during, or after boss fight. -still unknown These are the primary ideas being worked on and tested, with minor differences in attempts. I personally have been working to test these methods and explore options further. If you believe you have valuable info to add, please comment your ideas and experiences. We need a group effort as a community to try and figure these things out. The idea that this gatekeeper would be spawning for no reason other than to look at him from afar just feels wrong. There must be a reason. Perhaps it's all just part of a hard raid only fight mechanic that's yet to be seen, or maybe, it's ment for normal as well. Let's figure this out guys! Edit: will try to update as more info comes in. If you have proof of concepts for ideas, please post it as well. Edit: We have since found a way inside. We are working to test the ability to trade the sword to the person inside while crota is spawned. Edit: we have been able to get a sword to the top and to kill the gatekeepers as they spawn. The gatekeepers are just replaced by new ones as you kill them. No chest has been found so far. Edit: after killing Crota, if you jump up there, any remaining gatekeepers can be found just laying down on the ground, like they are taking a nap, very strange. Not sure what else is possible from here. Please comment ideas.