Horizon Zero Dawn's The City of the Sun follows A Seeker at the Gates.
If you're after help for other parts of the game, consult our complete Horizon Zero Dawn walkthrough and guide.
Olin's Apartment and How to Break the Hatch
Here, you'll meet up with an old contact in Erend, get to explore your first proper city, and meet a brand new tribe. Now through the gates and into a massive new region, Meridian lies some way to the West. The lands here are expansive and, at times, quite dangerous, with huge machines lining your route.
That being said, it's also an exciting new part of the world to explore, and the route to Meridian provides some of the most stunning vistas in the game.
Go to Meridian - Meridian's a little while away, and through a couple of areas inhabited by big, shiny, dangerous new machines, so save often as you discover campfires, and maybe think about picking up a mount.
Follow Erend - Once there, you'll be stopped by a city guard, only for Erend, the man who spoke so well to your Tribe back before the Proving, to show up and drunkenly encourage you in. It seems he's mourning the loss of his battle-hardy sister, Ersa.
Investigate Olin's Apartment - It's time to figure out what this Olin character with the Focus was really up to. Scan the apartment with your Focus until you find a secret hatch to a floor below.
- Find a way to Break the Hatch - the hatch is on the ground... so maybe something heavy from the floor above could break it? Head upstairs!
- Push the Stack of Ingots - Shove the conveniently-placed stack of ingots off the conveniently-placed open ledge down onto the hatch to break it!
Investigate Olin's Secret Workshop - Breaking the hatch reveals a hidden workshop room below Olin's apartment. Scan it with your Focus!
- Examine the Map - First up, check out Olin's wall map.
- Examine Olin's Journal - Next, his Journal on the table, for some interesting developments.
Talk to Erend - He needs your help finding Ersa, too. At this point your Main Quest line with branch again. You can finish off The City of the Sun and the quests which immediately follow, or, you can diver to The Field of the Fallen to get answers about Ersa.
We recommend prioritising the grander story for now, seeing as The Field of the Fallen has a much higher recommended level, which means finishing the current quest and getting some answers from Olin.
Find Olin at the Excavation Site - Head to the site revealed by the Map and Journal in Olin's apartment. Enter the Excavation Site - Head in and see what's going on there.
Kill the Corruptors and the Cultists - It turns out quite a lot! Two Corruptors and a load of Cultists await you, with a reluctant Olin held semi-captive in the centre of the large pit.
We recommend sneaking around the ledges at the sides of the dig site to take out the Cultist Snipers one by one, before talking the Corrupters from range by themselves. It'll make your life far easier than attacking them both head on with Snipers going at you at the same time!
Talk to Olin - With those tricky enemies defeated, chat with Olin down in the middle of the pit, and choose how to respond to his actions...
For more Horizon guides, explainers and advice, take a look at our main Horizon Zero Dawn guide and walkthrough hub, which includes guides to things like Horizon Zero Dawn's override Cauldrons and how to override machines, sorting out the Golden Fast Travel Pack for unlimited Horizon Zero Dawn fast travel, unlocking the amazing Horizon Zero Dawn Shield Weave Armour and Power Cell locations, and on top of that, for DLC players there's our hub for theHorizon Zero Dawn Frozen Wilds walkthrough and guide, a page on how to earn Bluegleam quickly, and finally, a handy guide to A Secret Shared and how to upgrade your spear in Horizon Frozen Wilds.
With Olin dealt with - one way or another - you now have another branching story on your hands. Erend is desperate for you to help uncover the circumstances of his sister's death, starting a separate questline in The Field of the Fallen.
That has a much higher recommended level though - and the main story, really, is more pressing after all - so we recommend a couple of the main quest missions to be completed first, starting with Maker's End.