Vex Crossroads Public Event
It is as Osiris predicted! A Vex Mind moves its servants between past and future!—Brother Vance, Vex Crossroads public event starting on Mercury.
When the Vex Crossroads event begins, the space around its area will transform. Two Hydras will spawn, called Gatekeepers. Killing one of the Hydras will make it drop two orbs, called keys. These need to be deposited at specific locations to close specific warp gates. Once two gates are closed, players can proceed onwards with the event. In the next area, the entire process must be repeated. As players close more gates, other will become accessible via different Vex cannons. After a number of gates have been closed, players must proceed to the final boss - the Gate Lord. He will be vulnerable for a limited time, so players must lower his shields at times by seizing more keys from the sub-boss Hydras. Defeating the Gate Lord will complete the Public Event.
To make this event Heroic use the orbs on the portals and wait until the catapult turns around. Jump on top of it and go to 1 of the islands on the side when the catapult has turned completely. Once you've reach the island, kill the Keeper of Ages Present and pick up the orbs that he drops. Throw the orbs to the center of island. It makes a Vex crystal vulnerable in the back of the platform. Destroy the crystal to create platforms. Follow the platforms to the top of the island and step on the plate on the roof.