A murder has been committed! The prime suspect is the daredevil acrobat Salto King, a star performer who packs the tent at Circus Roxi every night. He is accused of killing the wealthy Count Thierry, whose lifeless body was discovered in the villa of his girlfriend, Ellen Montis. Determined to prove his innocence, Salto King makes a daring escape to avoid arrest. Convinced that Ms. Montis is the one behind the crime, he pursues her across land, water, and air—with his faithful German Shepherd, Greif, constantly by his side.