In the royal castle, Prince Matthias feels like a prisoner. His father forces him to get engaged to Princess Beatrix, whom he does not love. Matthias takes advantage of a chance encounter with the rogue Tomas, who is his identical double. The boys swap clothes and agree to try on each other's lives for a day. In the morning, Matej is wrongly accused of theft and imprisoned. Tomas has to stay in the castle and although he tries to convince the king that he is not the true prince, no one believes him. The two boys must face a world they have never known before, grow up and learn to take responsibility for their decisions. Their reward will be that they both find true love.