The single-player campaign in Call of Duty: Black Ops Cold War experiments with a number of new mechanics, twists, and ideas and introduces a unique mission structure to Call of Duty. You can mainline it as you would any other Call of Duty campaign, but if you take your time to look around, talk to your teammates and read the evidence you come across, there's plenty hiding in Black Ops Cold War that is well worth your time to explore.

Case in point: side missions. There are two side missions in Black Ops Cold War: Operation Chaos, and Red Circus. In this guide, we're going to cover everything you need to know about Operation Chaos, including where to find all three pieces of evidence, how to solve the puzzle and how to decrypt the floppy disk.

Where to find Operation Chaos evidence
There are three pieces of evidence you need if you want to do Operation Chaos the right way. You can ignore the evidence and just play the mission as soon as it becomes available, but we recommend cracking the code and doing it properly.

As with all pieces of evidence In Black Ops Cold War, the three required for Operation Chaos are all found in other main missions. You're going to be fine if you end every mission with all pieces of evidence collected, so keep that in mind as you load up any main mission in the game.

Coded Message to Qasim
The first piece of evidence is the Coded Message to Qasim. It is found in the Nowhere Left to Run mission. To get it, you'll simply need to finish interrogating Qasim Javadi. It doesn't matter which choices you make, so long as you don't throw him off the roof immediately.

Numbers Station Broadcast
The next piece is the Numbers Station Broadcast, which you will find in the Brick in the Wall mission. To locate it, you must go after the optional objective: rescue/silence the informant Greta mentioned. Once you locate him and take out the Stasi guards in the room, you'll find a small radio on the table next to him. Pick it up.

Frontpage of the Observer Newspaper
Finally, the last piece is found in Redlight, Greenlight, the main mission that immediately follows Brick in the Wall. This is the hardest of the three to get because of how big the level is, but don't fret.

After the live fire exercise fight ends, the one where you have to take down Russian soldiers training to attack a fake US town, get down street-level and keep moving until you reach the end of that street. Once you come across the Capital Savings building, there should be a bar next to it. Head upstairs to find that level's third map. Once you take a picture of it, you will also unlock the frontpage of the Observer newspaper.

If you think you're in the right place but don't find the piece right away, check the top part of your screen. If you see a yellow message that reads 'In Objective Area', you're right where you need to be, so take your time and look around.

Obviously, you won't have all the necessary pieces until you finish Redlight, Greenlight. If you finish that mission without having all three pieces, you probably missed one or more in other missions. Go back to the board and see which of the main missions still have pieces you haven't picked up.

Once you have all three, it's time to decrypt the floppy disk.



Before we get started on decrypting the disk, you should know that the information each piece of evidence contains will be different for each player. Because of this, there is no single code or passphrase that can break the decryption for everyone.

What we will show you is how to solve the puzzles yourself, not give away the solution. It's a fairly straightforward process, so don't feel discouraged. That said, if you don't want to deal with some light puzzle solving, you can still play the mission all the same, but you're going to get a slightly worse ending.

To decrypt the floppy disk, we need a code as well as a passphrase. Here's how to get those.

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How to decrypt the Operation Chaos floppy disk
We'll begin with the newspaper clipping to get the code. After clicking Review Evidence, pick the newspaper from the evidence row. Once you examine it, a number of letters will start popping up, highlighted in red.

Write down all the letters, and try to rearrange them so that they spell the name of a US city or state. If you're feeling lost, open the Numbers Station piece of evidence and check the list of names there. The name of the city has to be one of those. In our example, we got O, S, N, O, U, H, and T, which spell out Houston when rearranged.

Once you figure out what your newspaper is trying to spell, switch to the Numbers Station Broadcast and check the four digits that correspond to the name of that city. You don't have to wait for the voice to say it, just look at the list. For us, that was 6461 - so that was our code.

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The next one is a bit tricky, and it's how we get the passphrase. We'll now go to the Coded Message. Once again, click examine to get the fullscreen view and more clearly check the missing numbers. As you can see, there are two sets of numbers, red and blue, with each set missing a number.

Our puzzle will be different to yours, so the only way of solving it is figuring out the pattern for each set of numbers. Let's start with red, in our example, we got 11, ?, 18, 20, 21.

As you can see, the numbers increase as you go from left to right, but the difference goes down with each number. If you still can't figure it out, try looking at it from the opposite direction, and it might make more sense. The solution here is 15. Write down the solution to your own puzzle and let's move on.

We're now only missing two more digits, so we'll have to figure out the missing number from the blue set. In our case, we got 66, 70, 74, ?, 82. This one happened to be easier, because each one is a fixed increase of four, which means the missing number is 78. Now, we have the full four-digit code, which in our example is 1578.

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Once you get both, return to the Broadcast and check which city corresponds to those four digits. In this case, it was Miami - this is your passphrase.

All that's left to do now is enter those details, and find out if you got them all right. Click Decrypt Floppy Disk and enter the four-digit code you got from the newspaper, then you'll be asked for the passphrase, which you should have from solving the numbers puzzle.

You'll know you got it right because of the information it will reveal, and the dialogue that plays when you do. Now, you just need to play Operation Chaos and take down Robert Aldrich. After you finish the game, look out for a cutscene with Hudson and Black recapping your campaign progress. It's there you'll see the result of your work.

Feel free to share what your puzzles were in the comments.