Lieutenant Colonel Ziganshin has already thought of everything: in order to live well and happily, you need to marry your neighbor Frida, a red-haired girl who is so attractive, touching and smart. She could fit harmoniously into his world and make friends with his children. But a series of terrible crimes investigated by Ziganshin increasingly distances him from his desired goal, from peace and rapprochement with Frida. Is simple human happiness really impossible for him?