The toughest Deathloop puzzle hides loads of items to make finishing the game easier

The Deathloop Fristad Rock bunker is locked up tight, and to get inside you'll need to solve one of the most difficult puzzles in the entire game, but it's absolutely worth taking the time and effort to infiltrate this Storm Shelter with a doorbell. Get inside and you'll be able to access the Intelligence Archives, providing a wealth of intel along with a selection of helpful gear, and all of this will make your journeys through the loop easier to manage. The area itself feels like the game's biggest secret, as it's a room full of useful items to help you finish Deathloop more easily, which is hidden behind a door that you can open right from the start.

However, it's a tough puzzle that isn't clear, so it's easy to miss it until it's too late, leaving you finding out some of its secrets the long way around. For example, I only solved it after finishing the story, leaving the gear, clues, and Deathloop codes it provides next to useless. So don't make my mistake - if you're only just getting started, make a point of popping that door as soon as you can.

Obviously, the information coming up could have some spoilers if you really want to work things out for yourself, so stop reading if that's the case. With that said, we'll avoid anything too disastrous and if you want to find a bunch of important Deathloop leads, gear, clues, and codes right at the start of the game, then read on.

The Deathloop Fristad Rock bunker intelligence archives

You can find the Deathloop Fristad Rock bunker on the coast, to the left as you come out of the tunnels. The door is hidden behind some wood you can smash and you'll discover a doorbell that doesn't initially do anything. However, give it a good 20 or so rings just to be sure, as part of this puzzle involves ringing doorbells a certain amount of times, and at this point I don't know if you can do that right at the start or you need to trigger later events first.

If the doorbell doesn't work then come back in the afternoon or evening when the tide will have gone out. Investigate the new lower shore area to find some poles and a light near a crack in the rocks that will take you inside the Storm Bunker. 

Once you're in, you'll find a door with three locks, a note with the first combination and an audio diary from a soldier. This diary will tell you that a message has been hidden in a morning radio transmission so you'll need to find one of the hackable radios you can use for distractions in the morning. There's one in the Transmission Tower overlooking Fia's bunker for example. 

Hack the radio in the morning and you'll hear a message like this, but not exactly the same: 

"M 13. Nine. H 26. Nine. R 33. 16" 

The coordinates will be the same, as they refer to map locations, but the single numbers without letters will be different for you, as these refer to the number of times you have to ring a doorbell to open the related door. 

M13 - Karl's Bay location 

The M13 coordinate refers to the Karl's Bay map and will take you to a warehouse near the Treasure of the Ice exhibit. Press the doorbell the same number of times as in the message and the door should open, giving you access to the Dusty Storeroom. 

Inside you'll find a Spiker that will disable any security systems you fire it near, some info about a vantage point over the hangers (this alludes to a panel you can smash during the Fathoms of Lament game you can play in the evening) and one of the codes for the Fristad Rock Intelligence Archives.

H26 - Updaam location

The H26 coordinate leads you to a building next to Otto's Firework Shop in Updaam. Look for the door into the building to the left of Otto's and head up the stairs inside. You'll find an apartment door with a doorbell. Ring it the number of times mentioned in the message and you'll get in. 

Once there you'll find a Volpat Trencher shotgun that will inflict more damage when you're airborne, another Fristad bunker code, a note about one of the Deathloop Visionaries Aleksis liking chocolate beer (one of the ways to identify him) and a note about 2-Bit, Charlie's computer, being a potentially useful contact. 

Opening the Fristad Bunker Intelligence agency door

Once you have all three codes you'll be able to open the door inside the Fristad Rock storm bunker. Inside you'll find loads of info about Colt's past and Two Tribunal pistols - one that tags enemies and another that does more damage to tagged enemies. However, the real value of what's in here is more info. If you access it right at the start you'll unearth a load of useful details that can save you hours on trying to find it out yourself. The info included is this: 

• Delivery booth codes to access on demand delivery of cranks, batteries, turrets and null field generators. 
• The maintenance tunnel code so you can get from hangar 1 to hangar 2 and sneak up on Harriet in Karl's Bay (if you have the gas immunity Trinket).
• Info that Egor's Aether slab gets you past security systems like turrets and cameras.
• What wires you need to cut to disable Fia's reactor.
• The code for Ramblin Frank's security system and how to access the security panel.

All that might not sound like much, but some of the things you can find here could only otherwise be discovered by hours of play. Discovering Aleksis like chocolate beer, for example - a potential way to identify him - could mean sneaking into his heavily guarded party and exploring until you find someone talking about it in a specific room. The notes and info here cover codes, routes, and options that you might take ages to find, if at all, while playing. Being able to find so much so fast is an incredible secret for the game to hide in plain sight.