Horizon Zero Dawn's The Looming Shadow follows on from us claiming the all important Master Override back in the previous quest, The Mountain that Fell, meaning you're all set for the final battle.
But Meridian isn't just yet, and HADES is set to resurrect a massive horde of machines to launch the assault.
If you're after help for other parts of the game, consult our complete Horizon Zero Dawn walkthrough and guide.
What to do at the Defense Sites and how to review preparations
The Looming Shadow is all about laying the groundwork for the city's defense, and making sure you personally are just as prepared as the city before triggering the final attack.
Go to the Palace of the Sun - Simple enough, for now you just need to get back to the heart of the Meridian-based tribe and warn them of what's to come.
Talk to Sun-King Avad - Prepare Avad for the battle ahead by filling him in on recent events.
Talk to Blameless Marad - Marad, despite being Blameless, is in charge of organising the defences, and talking to him nearby will set you up for the final few objectives before the main battle.
Visit both Defense Sites (Optional) - Uou don't need to visit the Defense Sites to start the final battle, and the only benefit is a soft one, preparing you personally by allowing you to explore the two areas where you'll be getting stuck into the fight.
Review preparations at the Ridge (Optional) - at the Ridge, there are special cannons, like grenade launchers, for you to use in fending off attacking enemies. You can practice with them here, before it really counts, if you like.
Review preparations at the Spire (Optional) - Up at the Spire, there's no practicing to do, but you can chat to your various old accomplices - Sona, Varl, and Erend - who'll be helping out there when the battle comes.
What to do before the Final Battle
Rest Before the Final Battle The game makes it explicitly clear, but just to be extra sure here: once you rest at the bed in Olin's Apartment, the battle will start, and you won't be able to go exploring for more XP or gear, or purchasing any more goods, once it does.
So make sure you're absolutely prepared for the battle ahead before you do so. It's also worth noting that this mission suggests a pretty high level to complete, but we tackled it a few levels under recommendation, so only go grinding if you feel like it yourself.
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 those preparations made, and you now well-rested at Olin's Apartment, the Final Battle begins, along with the last mission: The Face of Extinction.