Black Ops: Cold War - Operation Chaos mission: How to Decrypt the Floppy Disk Code explained

How Operation Chaos and Decrypting the Floppy Disk works

Opening up after completing the Fracture Jaw mission, Operation Chaos appear on the evidence board alongside another side-mission Operation Red Circus.

Within is a side-mission you cannot access until you Decrypt the Floppy Disk. To do that, you need to enter a code and a passphrase, which are gathered from finding evidence in missions.

You need to play through three campaign missions - Nowhere Left To Run, Brick in the Wall and Redlight, Greenlight - and find the hidden evidence in each. Once you have, and can return to the safe house, then access the mission board, and set about looking through the evidence to solve the puzzle and access the mission.

First things first, then - let's find that evidence. You can find all evidence on your first playthrough of a mission, and if you forget to pick up any, remember you can replay any mission from the mission board, or from the Campaign area of the main menu.

Nowhere Left to Run evidence location for Operation Chaos explained

Halfway through the opening mission Nowhere Left to Run, you interrogate Qasim on the rooftop.

Select the dialogue choices here that do not throw him off the roof. Doing so will give you the evidence.

Once you have it, the choice of what to do next is yours - whether it's capture, throw or release.

Brick in the Wall evidence location for Operation Chaos explained

About halfway during the third mission, Brick in the Wall, you will meet an informant in a bar. They will give you an optional objective - Rescue or Silence the Informant - which you can undertake shortly afterwards.

The side-quest marker will appear when you travel upstairs and reach the outside balcony of the next building. Make your way there - it's easy to get to from the balcony if you hug the left wall and travel through the buildings.

When you are back outside, kill the guard outside the door, pick the lock, and enter. There are three guards sitting around the informant in the basement here, all of which can be picked off without being spotted.

Whether you shoot or rescue the informant is up to you, as the evidence you need is on the table.

Now continue the mission. Note there is some Operation Red Circus evidence to collect later, which you may as well get on the way.

Redlight, Greenlight evidence location for Operation Chaos explained

In the Redlight, Greenlight mission, there is an optional objective to Gather Photo Intel across the mission. These are maps dotted throughout the level, with six in total to find - and finding three of these will give you the Evidence you need for this mission.

Any three will do. To help, our dedicated Redlight, Greenlight Photo Intel locations page will show you where to find all six.

How to Decrypt the Floppy Disk and solve the Operation Chaos puzzle

Once you have all three evidence pieces, go to Operation Chaos on the mission board, then inspect each piece of evidence closer to find their clues.

You need to find out a code (four numbers) and a passphase (a city) from linking the details in all three files. Having a pen and paper close by might be handy, though remember you are allowed to get it wrong and try again if you mess up anything.

Final important point - for every player, the clues you are given and the answers you need to find are random for each player. As such, you need to understand how the puzzle works in order to solve it.

Here's how you get the clues you need, evidence by evidence:

Front Page of the Observer

This one is the simplest of the three - there will be some red letters which stand out against the rest of the black newspaper copy - in our example, it is ENERDV. Remember, yours will be different.

A Coded Message

There will be a row of numbers, with two cells containing question marks. The aim here is to split up the coloured numbers into their own sequences, then work out what these missing double digit numbers are based on the pattern presented in the sequence.

In our case, the red numbers are 13, ??, 27, 31, 33 - with the missing number being 21. Here, the numbers increase by half increments each time - the difference between 13 and 21 is 8, 21 and 27 is 6, 27 and 31 is 4, and 31 and 33 is 2.

Meanwhile, the black numbers go 87, 90, 93, ??, 99 - with the missing number being 96, as the pattern goes up three each time.

This gives us the four digit code 2196. Again, yours will be different - but we'll use ours to show how to solve the final steps.

If you're stuck on either pattern, remember you technically need only one set of numbers - which we'll explain why in a second.

Numbers Station Broadcast

This is a list of cities and numbers, both of which you need to focus on. (You can ignore the audio - it's simply reading out what's on the page).

One of the cities will be an anagram of the red text in Front Page of the Observer - in our case that was ENERDV, so this is Denver.

One set of numbers, meanwhile, will fit into the question marks in A Coded Message to complete the pattern. In our example, this would be 2196. (You might only need the start or end two numbers here if you are struggling to work out the full A Coded Message sequence).

There is now one extra step to take. You now need to look at what the respective numbers and city next to these are to get the final code and passphrase. So for us, looking at Denver and 2196, the corresponding entries next to them are Boise and 7167.

Once you have the solution, head to Decrypt Floppy Disk and enter them - numbers first, then letters. This will then unlock the Operation Chaos side-mission.

The mission itself is straightforward enough - simply follow the points, take down the target, and make your way back to the helicopter.

If you haven't already, it's worth also completing Operation Red Circus before you move on to the final set of missions.