Vincenc Babočka, an insignificant employee of the police station, plays detective in private, convinced of his exceptional abilities. However, a vacation in Karlovy Vary unexpectedly gives him the opportunity to prove what he is really capable of. He is mistakenly considered to be the international adventurer Leon Weber, who is being pursued by the police. He decides to take advantage of the confusion and expose Weber's accomplices, who are planning to steal diamonds belonging to the Maharaja of Yohir. According to Weber's plan, he meets the Maharaja disguised as General Naryshkin, but everything only works out until the real Weber appears in town...