Nina Stepanovna is used to living alone. She knows the value of every kopeck and is not used to complaining about life. When her son sends her a robot cat named Mars, she is not happy about the gift, but arguing is useless. Graphite-gray fur, amber eyes, a toneless voice—the device is supposed to monitor her health and remind her about medications. But Mars takes his task too literally. He speaks in his owner's voice to scammers, single-handedly stops a courier, intimidates hooligans, and even resorts to a desperate act when he sees that Nina doesn't have enough food.

An artificial intelligence with the stubbornness of a machine breaks the rules to protect her. And the elderly woman, used to relying only on herself, tries to explain to him that care is not only efficiency but also respect for another's choice.

They learn to negotiate. Through trial, error, and dangerous situations. Because sometimes even the coldest mechanism can warm a heart if it is allowed to doubt.