Tango, panthers, love - a short story

In this short story a man falls in love in a tango dance evening, but the beloved woman belongs to a frightful skin-changer group, called Pantheras. The main character, Alfredo tells the story of the death of her love, Martina, and how he reacted unexpectably. The story is set in a world where humans are aware of the skin-changers, since the so-called Tear of the Veil. The skin-changers became very powerful and immersed in the criminal world.