In Mission six: The Dust District, you will encounter the Jindosh Lock. The Jindosh Lock combination is randomized and different for every player and changes with each playthrough. However, you can easily solve it every time by creating a manual save game at the start of the mission, when talking to Meagan Foster (before killing either of the gang bosses). Then, kill and deliver one of the gang bosses to the other. They will give you the combination for your Jindosh Lock. Write down the combination. Then, reload the manual saved game you previously created. Go to the Jindosh Lock and enter the code you wrote down to unlock it and get the "Eureka" achievement. This is also very useful during a stealth run. Use the same method, then reload the manual save and enter the code to skip the entire mission. After opening the Jindosh Lock, the mission will immediately end.