The events of the series "Mosgaz. Spider" take place in 1967 in the Armenian SSR. The Kalachyan brothers steal one and a half million rubles from the state bank - a huge sum for that time. Meanwhile, in Moscow, someone kills a fashion model from the House of Fashion. Both of these particularly dangerous crimes fall into the hands of Major Cherkasov's operational group. Ivan Petrovich knows how to expose the culprits, but he will need the help of his junior colleagues like never before. He infiltrates his own person into the House of Fashion.