The Mercury public event is one of the few new activities you'll be getting up to in the new Curse of Osiris DLC.
Vex Crossroads spans almost the entirety of the new Mercury play space, and as with other public events, has a unique set of requirements to unlock its Mercury Heroic variant.
How to complete Mercury public event Vex Crossroads
While at first intimidating due to its size, the three steps required to completed a reasonably simple and quick, and obviously goes much faster with a compliment of other players joining you.
Phase one: Seize keys from Gatekeepers to shut down the warp gates
The sole public event on Mercury looks like it is two events occurring at the same time, but it's actually showing the first phase takes place across two areas at once.
This first phase has you shut down four warp gates, two at either end of the patrol space. Start at one end, and find the Gatekeeper, a named enemy called 'Keeper of Ages Present'.
Once it's downed, it'll drop orbs. Pick up one of these orbs, and take it to one of the two gates on the upper ledges on the outside of the raised area to dunk it. If the orbs disappear, more should spawn up the steps near the launcher.
Perform this for both gates on both sides, making for a total of four gates.
Phase two: Travel to the island to shut down its warp gate
On both outer edges of Mercury are islands, which one of the launch pads near the above gates will take you to. When you land, it's a similar process as before - find the Gatekeeper, destroy it for orbs, and drop them into the central gate.
You then take the launcher back, go to the far other side, and repeat at the second island. It should be noted it's this phase that has the Heroic requirement, which we'll discuss in more detail toward the end of this page.
Phase three: Defeat the Gate Lord
With the second island done, head back via the launcher and go to the central-most- rea, where a towering Vex - the Gate Lord - will be waiting.
This is a simple case of putting as much damage in as possible. With a handful of you it won't take long at all, and once it's downed, the event is over, giving you two treasure chests to choose from.
Enjoy your two Tokens and a blue.
Season of the Lost is here, with new Exotics such as the Ager's Scepter and the long-awaited arrival of crossplay. New activities include the Wayfinders Voyage, the Astral Alignment activity and finding Atlas Skew, Trivial Mystery, Enigmatic Mystery, Parallax Trajectory and Ascendant Anchor locations. Elsewhere, we've seen new Nightfall weapons such as the Uzume RR4, Plug One.1 and Hung Jury SR4. Other recent new features include transmog and materials Synthstrand, Synthcord and Synthweave, the Splicer Gauntlet and Decrypted Data used to upgrade it.
How to activate the Mercury Heroic public event
The Heroic activation comes during one very specific part of the event.
When you travel to the first island as part of the second phase, you'll destroy a Gatekeeper and drop an orb in the centre, before taking the launcher back to the main Mercury setting.
However, when you drop the orb and before you take the launcher, a floating diamond will appear on the outer edge of the island. You must destroy this as soon as possible to trigger a platform.
Leap up onto it, and two diamonds appear. Destroy these, and another platform and another set of diamonds will appear.
Destroy these, and a final platform will take you to the top of the island. Stand in the middle of the plate and the Heroic version of the event will activate.
While you can do this solo, the diamonds require a high amount of damage in a short space of time. Take too long in any set of diamonds, and it will disappear and halt your chance of getting the Heroic version - and there is no second attempt on the other island that follows.
As such, it's best to bring powerful weaponry and / or a friend to help you activate the Heroic.
The Heroic version then adds Gatekeepers in the final phase, requiring you to get another set of orbs from specific enemies and dunk them from launchers to lower the shield of the boss.
As with other Public Events, is well worth activating for fairly little effort but can be easy to miss, but is well worth doing for some extra loot and bonus XP.