If you've completed the story campaign for Call of Duty: Black Ops Cold War, you've already had your fill of cool experiences. But sitting down with Mikhail Gorbachev and averting nuclear disaster are just the beginning. The game is packed with more secret operations, secret meetings, and Cold War intrigue than you can shake a hammer and sickle at. But you don't need a full load of ammunition to discover all its secrets.

To properly solve the mysteries behind the Operation Chaos and Operation Red Circus side missions, you'll need six key pieces of evidence hidden throughout the game's core campaign. Once you have locked, loaded, and overrun the evil-doing communist sympathizers, you will understand most of the story. However, gamers who want to fully enjoy the story are advised to holster their hardware and read our detailed guide to finding this off-the-beaten-path information.

Each side mission requires three pieces of evidence, starting with the main mission Nowhere Left to Run to secure the first piece of evidence for Operation Chaos.

Much of the information comes in the form of physical items, but this first piece will be obtained through interrogation; catch up with the rogue Quasim during a rooftop chase before the finale on the airfield in Nowhere Left to Run. Instead of executing the target, you need to talk to him. Specifically, ask, "Who is Arash meeting with?

Do so, and you will be the first holder of evidence: a coded message.

Next, take on the "brick in the wall" and discover evidence of the Numbers Station broadcast

This mission has an optional objective: to track down an informant named Richter. Complete this stealthy side quest by unlocking locks and flicking off guards until you find Richter tied to a chair in the basement. You can rescue Richter by killing the three clueless captives, but the real objective is a vintage audio reel on a table behind an equally vintage camera.

While you are in "Bricks in the Wall," you can also scoop up evidence from Operation Red Circus (the only mission to include two pieces of evidence). Near the end of this mission, you will snoop around Franz Klaus' private residence. You will need Mr. Krauss's ledger, which is on his bedside table.

Securing it will not be easy. Klaus and his family are home and roaming around, so when you go to the master bedroom, sneak into the shadows.

The final piece of evidence for the Operation Chaos side mission is the front page of the Observer in Red Light, Green Light. You will eventually unlock this newspaper, but you will actually spend most of the mission searching for a special item to photograph. There are six pieces of information that can be photographed, but only three of them need to be photographed to unlock the evidence. With this in mind, your best bet is to photograph the first three items.

When you arrive at the secret Soviet base, you will be prompted to take pictures as part of the critical path. Shortly thereafter you will find yourself in a guard house. Equip the camera again and photograph the map and blueprints on the wall. Once you infiltrate the base, you will soon find yourself in a long hallway. The hallway has several open doors and many guards. After clearing out the threats, proceed through the first door on the left. On the wall to the right is a map that wants to be photographed.

Once you have the two photo info, hide the camera for a bit and take a break from gunplay. Defeat all the enemies on Faux American's main street and head to the second floor of the building across from the fast food burger joint. After a short search, you will find a map attached to a brick wall. Taking this third photo adds an aspect of "Observer" to the evidence.

While sneaking around in the "brick in the wall," you have already secured the first piece of evidence from Operation Red Circus, so only two more remain: the first is the "activity report cassette tape" from the "Echoes of the Cold War" mission; the second is the "Observer" cassette tape from the "Echoes of the Cold War" mission.

There is quite a bit of fighting at the beginning of this chapter, but once you have soiled the snow with enemy blood, zip line to the large communications base. Defeat the guards coming out of the communications base and search the abandoned building for evidence. Among the rubble and old computers, you will find a desk with tape on it.

The final piece of evidence in Operation Red Circus is also the most tedious game to discover, as its location changes randomly. In the "Desperate Measures" mission, you will be looking for a "dead drop-listed wristwatch" at the KGB headquarters.

Once you meet Gorbachev and his goons, you will be required to turn off the building's surveillance cameras. Once this important objective is completed, you are free to search for evidence. The watch may be in the server room, the records room, or behind some other closed door. The best bet is to use the maps provided, use stealth by hiding bodies, and systematically look around the room, checking various desks and tables for any last clues.

It is important to note that if you have already completed the Black Ops Cold War campaign, you do not need to replay the entire campaign to find the six pieces of evidence. Once the missions are unlocked, you can access them immediately (and in any order) and focus on securing the hidden items. Even better: once you've acquired the information, you don't have to complete the mission. Simply scoop up the evidence and wait for the game to autosave.

Additionally, while collecting the various items in the order recommended above is certainly welcome, there is no required order. Choose the path you prefer and enjoy the hunt.