Three friends find an old note in the archive from which it follows that in a part of the Moscow dungeons they are familiar with, there is a passage to a certain location. The author of the message warns that this is a very dangerous place and must be isolated. The spirit of adventurism pushes the guys to rash actions and now they are already inside, the way back is cut off. How our characters will get out, what awaits them, will they withstand all the tests that the events of bygone days will present to them, and will everyone survive - read in the book Moscow Dungeons.