How to get the Firebrand Bruen from the secret subway Easter egg by solving the City Hall puzzle

The Warzone Firebrand Bruen subway metro puzzle is a really tricky Easter egg, that will see you trying find the solution to a numerical puzzle as a room fills with gas. Succeed and you can earn a new Bruen Firebrand blueprint but you will die loads trying. Here's how to maybe reduce the death count just a bit in this Call of Duty Warzone season 6 task.

This is a multi stage puzzle where you have to first head to Downtown in Warzone to solve a code that will then let you summon a special train from the Airport Warzone subway metro station to access a room full of loot and the Firebrand Bruen.

Here's how it all works.

Firebrand Bruen Downtown City Hall puzzle

The first thing to do is drop in on the Town Hall directly under the 'O' in Downtown as you're parachuting. The central double doors on the side shown in that picture up there will be closed at the start of a match, and if anyone is inside trying to solve the puzzle. However, if the puzzle is solved, or the people inside die, both doors will pop open. Either way head in and prepare to try your luck (or grab loot from anyone before you who died trying).

Once inside head over to the small silver keypad at the back of the reception area on the right and enter this code:

Warzone CityHall Code: 2179

When you input that, the doors will lock and gas will flood the room. You now have a little over two minutes to work out the code for the next stage. What you need to do now is run around the side rooms looking at the pictures and noting the numbers underneath.

There are seven pictures and the numbers beneath them are randomized so you'll need to make a note of them all and try and remember the number and what each image looks like.

Now you may have noticed that the last picture is slightly missing. We'll get to that in a moment.

Once you think you've got the numbers and pictures memorized, head over to the blue computer screens for the next stage of the challenge.

Activate the screen and it will show you tiny fragments of some of the paintings, followed by either a positive or minus number. You'll need to add and subtract the numbers to and from the images/numbers you think the picture fragments repent and write them down. This will give you four numbers in a sequence.

Now, remember the missing picture? If you see this beardy man, that's the missing picture. You can tell because it's slightly different to the two other beardy man paintings. It's obvious really.

This sequence will only play once though, so you'll have to be fast and once the sequence has played you'll see this jumbled code pad.

It looks like nonsense but the way it works is that the numbers are broken into top and bottom halves. The first four times you enter anything you'll fill out the top row, and the next four times the bottom row. So you really have to think about the shapes of the top of the numbers first, then the bottom halves.

Remember, you've only about two minutes and 20 seconds to do this so... good luck.

Once/if you get the code you'll need to make your way to the Airport subway metro station and find the room at the back beyond the double doors. There will be some huge green screens you can interact with if you've solved the City Hall code. Assuming you've completed all the steps so far you'll be able to override the terminal and the next train that pulls up to the station will take you to the magic loot room (which is somewhere under Dam). You'll know if you're on the right train as it'll say 'Maintenance' on the destination board, instead of one of the usual stops.

When the train stops you'll be at a secret station packed full of high level crates and loot. There will be two double doors on each platform - behind one you'll find the Firebrand Bruen, and behind the other will be another big green screened terminal you can interact with to 'initiate departure sequence'. Grab everything you want before you do that, though, as once activated the train will take you back to the airport the next time you get on it. There's no other way out either as the exits are caved in.