Die schwarze Natter (1913)

Two agents from different sides are working in a circus, one - the Schwarze Natter (Black Adder)- as a dancer, the other as a horseback artist. The Schwarze Natter is informed that the other is receiving information by one of the visitors this night, who is also in love her. She is trying to get him and the information herself, making it look like the other side has her finger in this incident. But an officer of the local police had an eye on them, because some things happening before made him suspicious and starts playing his little game.