Operation Chaos in Black Ops Cold War: How to Decrypt the Floppy Disk

Operation Chaos is an optional side mission in Call of Duty: Black Ops Cold War, and you must decrypt a floppy disk before you can launch it. You collect three pieces of evidence across three story missions, solve two small puzzles to get a code and a passphrase, and enter them at the evidence board. The answers are randomized for every player, so the steps below show you how to solve your own puzzle rather than giving one code that will not work for you.

Looking for the CIA programme? Operation CHAOS (MHCHAOS) was a real CIA domestic spying programme that ran from 1967 to 1974, kept files on thousands of Americans in the anti-war and civil rights movements, and was exposed by Seymour Hersh in The New York Times in December 1974. The game borrows the name. The Operation CHAOS article on Wikipedia covers its history.

Quick answer: the Operation Chaos floppy disk in 5 steps

1. Unlock the evidence board by playing the opening missions up to Fracture Jaw. Operation Chaos then appears on the board in the safehouse.
2. Collect the three pieces of evidence: the Coded Message (Nowhere Left to Run), the Numbers Station Broadcast (Brick in the Wall) and the Observer front page (Redlight, Greenlight).
3. Get the code: unscramble the red letters on the newspaper headline into a city from the Numbers Station list. That city's four-digit number is your code.
4. Get the passphrase: fill in the missing red and blue numbers on the Coded Message, join them into a four-digit number, and find the city that number belongs to on the Numbers Station list.
5. Decrypt the floppy disk from the Operation Chaos menu with the code and the passphrase city, then play the mission before you start End of the Line.

Where to find the Operation Chaos evidence

You need all three pieces. Without them the floppy disk cannot be decrypted.

After Redlight, Greenlight you cannot open the briefing straight away. Play Echoes of a Cold War to get back to the safehouse, then open the evidence board and choose Operation Chaos.

How to decrypt the floppy disk in Cold War (code and passphrase)

Open Operation Chaos on the evidence board and select Examine Evidence. Everyone gets different letters and numbers, so work from your own copies.

Step 1: The floppy disk code (Observer front page)

1. Open the front page of the Observer. Red letters are highlighted in the headline.
2. Write the red letters down and unscramble them into one of the city names on the Numbers Station Broadcast.
3. Open the Numbers Station Broadcast and note the four-digit number next to that city. That number is the code.

In my playthrough the red letters were A-H-N-L-E-E, which unscramble to Helena, and Helena was listed as 1479 on the broadcast. Your city and number will be different.

Step 2: The passphrase (A Coded Message)

1. Open the Coded Message. Two rows of numbers have a question mark in them, one in red and one in blue.
2. One row changes by the same amount each time. The other changes by a growing (or shrinking) amount.
3. Work out each missing number, then put them together as a four-digit number (a single-digit answer gets a leading zero).
4. Find that four-digit number on the Numbers Station Broadcast. The city next to it is the passphrase.

My red numbers were ?, 10, 18, 26, 34: each step adds 8, so the missing number is 2 (written 02). My blue numbers were 26, 27, 29, ?, 36: the gap grows by one each time (+1, +2, +3, +4), so the missing number is 32. Together that gave 0232, which the broadcast listed as Detroit.

Step 3: Enter it at the evidence board

1. Back in the Operation Chaos menu, choose Decrypt Floppy Disk.
2. Enter the code from Step 1 (in my case 1479).
3. Enter the passphrase city from Step 2 (in my case Detroit) and confirm.

The disk opens and gives you the location you need to start the mission.

What the Operation Chaos mission involves

The decrypted disk points you to Robert Aldrich, an ex-CIA officer helping the Soviets build a spy network in the United States. The mission sends you into the desert to fight through to a hotel, find and kill Aldrich, photograph him as proof, and escape to the helicopter. The rooftop is exposed with little cover, so keep moving on your way to the extraction.

Deadline and endings

• Finish it before End of the Line. Starting that story mission locks you out of the evidence board, so complete Operation Chaos (and the other side mission) first.
• Missed a piece of evidence? Replay the story mission from the campaign menu and pick it up.
• Endings: side mission outcomes change the short cutscene at the very end of the campaign, not which main ending you get.

Common mistakes

• Using someone else's code. The answers are randomized, so a code from a video only works for that player's save.
• Mixing up the two cities. The newspaper gives you a city, and you enter that city's number. The coded message gives you a number, and you enter that number's city.
• Dropping the leading zero. If a missing number is a single digit, write it as two digits (2 becomes 02) before you look it up.

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