Meta: If you find this kind of puzzle fun, I'd like to make a complete series with the same style. Let's see how it goes!
The Babel Brotherhood is composed of people from all around the world.
Two members of the Brotherhood, codenames Madrid and Washington, were on a dangerous infiltration mission to retrieve some secret documents. They were already inside the building, and Madrid was deactivating the silent alarm for the door of the office containing the documents. They both knew that if he failed, they would need to abort the mission immediately and run to the exit as fast as possible to avoid getting caught, and if he succeeded, they would need to quickly enter the office and retrieve the documents.
After some time working on the alarm, Madrid suddenly exclaimed a single word. Simultaneously, he opened the door (as he had deactivated the alarm successfully) and Washington started running in panic towards the exit.
What did Madrid exclaim, and why did Washington ran towards the exit?