Legend transmitted from one generation to another. Knife highly secret, because the arming of the elite squads Soviet saboteurs. Despite the extreme secrecy associated with this knife, about half the people who know about it, keep it in the hands, and the other half even owned them, but in time lost.

Inside the knife battle is contained metal mercury, which allows combat saboteurs achieve several goals. First, Mercury is balancing blade in flight, allowing confident of striking any target in the distance. Secondly, mercury, penetrating into the body of enemy, causing additional damage to enemy authorities, causing severe poisoning. The third in the hopeless situation of military spy may commit suicide, taking mercury. The fourth mercurial knife is an indispensable tool in a situation where medical care is not available for obvious reasons.