Destiny 2 guide: complete campaign walkthrough and guides - updated with Curse of Osiris

After figuring out what we needed to know from Io’s pyramidion in Deep Storage, it’s time to return to Mercury to find the map of the Infinite Forest. 

If you're looking for help with a different campaign mission, check out our complete Destiny 2 guide.

Destiny 2 Curse of Osiris - Mercury: Tree of Probabilities 

You can begin this quest by interacting with its activation flag just outside the Lighthouse’s front gates on Mercury.

You’ll be heading back through the gateway you first encountered in Beyond Infinity, so go straight ahead from the mission start point to reach it. 

Cabal will be patrolling the area in addition to Vex this time too, and those nasty Scorpius turrets will be peppered around here and there, so make sure you deal with them before they can get the drop on you.

Once you’ve powered through the gateway, head on through and you’ll be back in the Infinite Forest. Bungie’s procedurally generated platforms will show up again here too, so just do what you’ve always been doing until now; killing the enemies, activating the doors at the end of each section, and moving onto to the next platform to repeat the process.

If all goes to plan, you should find yourself heading into one of those cylindrical towers by the end of it. Go through, and you’ll be on Mercury in a different timeline, fighting Cabal in an open plain.

You’ll have a ton of Legionaries, Psions, and Centurion all looking to hurt you, but you’re gonna have to kill them all to progress, before using your sparrow to make the jump to the next area, where even more Cabal can be found.

You can ignore them, though, to stay on your sparrow and continue through the giant pathway (complete with rotating lasers) up ahead. Keep moving down into the cavern below, avoiding more stationary lasers inside, until you reach Atlas Grove; a wide open path populated by Legionaries, Incendiors, Psions, and Gladiators. 

Fight your way through the armies (remember to aim for the explosives attached to the Incendiors’ backs) until you make it inside, where you’ll encounter a boss fight with a guy name Vallus Thuun. 

You only need to deplete his health a little before he departs and leaves behind some adds (and more laser traps) for you to deal with, at which you point you can keep following your marker to catch up to him.

He’ll engage with you three times as you progress through the area, but defeating him on the third will kill him off for good. Watch out for his heavy cannon and charged melee ability when fighting him, as they can put you down almost instantly if you’re in the wrong place at the wrong time. 

From there, you can head on towards the map behind the now unlocked door, thus ending ending the mission and setting events in motion for Hijacked

For more Destiny 2 walkthroughs, guides, tips and tricks, make sure you visit our Destiny 2 guide hub, or check out our Destiny 2 Curse of Osiris tips for the things we wish we knew before we started playing the expansion.

Next mission - Nessus: Hijacked