British intelligence resident Mi-6 is hunting for top-secret developments of the Russian design bureau. The spy fits into the life of scientists so harmoniously that it is almost impossible to guess his true essence. That’s why Timofey Sergeev, a student at the water institute, who happens to be nearby, takes everything at face value, makes friends, falls in love, and carouses – as befits a happy young man. And yet, there comes a moment when he begins to understand that a dangerous, but almost imperceptible intelligence game has unfolded around him and he unwittingly found himself drawn into it...