The container with polonium is already in London, in the hands of former FSB officer and now defector Vitovchenko. The multi-step operation of Western intelligence services to discredit the secret organization of Russian veteran intelligence officers “Shield and Sword” has begun. Such an operation can only be carried out if you have your own person – a “mole” – among the members of the organization. Colonel Karaev is tasked with checking all members of the organization, and all of them are proven and absolutely reliable people. Nevertheless, the “mole” is among them, and in order to figure it out, you need to find a non-standard move. The Colonel decides to take a risky step...