FSB Colonels Viktor Loginov and Grigory Kashcheev are mortal enemies. And how could it be otherwise: Kashcheev is a traitor who turned into a criminal, he has a number of terrorist acts on his account, and he continues to carry out daring actions in the south of Russia. Loginov has been hunting for this werewolf for a long time, driving him into a corner more than once, but Kashchei is dexterous and resourceful, like a snake, and just as insidious and dangerous. But now the situation is clearly not in his favor: he is locked in an underground grotto, the exit from which is only through a deep well that goes out into the sea. Will the terrorist really leave this time too?