An ordinary weekend of an ordinary family turns into a detective. Parents leave their eldest son Zhenya to look after the younger Kolya, and they themselves go to celebrate the wedding anniversary. As luck would have it, it’s Zhenya’s friend birthday too, and now he can’t go there. But a miracle happens. A car from a social center comes to take Kolya. Big brother is free! And then Kolya - a teenager with a mental disability, like a gullible child - disappears, gets lost in a huge city... What will Zhenya, his girlfriend, their friends do? What will they choose - will they continue to celebrate or rush in search of Kolya? And how will this choice change them?