An irresistibly attractive tango teacher, Corrado Fanti, is found murdered in his tango school. He has been poisoned, and his home ransacked in search of something. The investigations concentrate on the tensions and romances surrounding the handsome teacher's relations with his female students, perpetually competing for the privilege of dancing - and more - with him. While investigating, Terzani and Rex discover that the school's female tango teacher is being targeted by the same killer.