El Tercer Brazo by Larry Niven

In a world where humanity has developed the ability to harness and manipulate an extra limb through advanced technology, society is thrust into a new era of possibilities and challenges. This additional appendage, known as the "third arm," becomes a symbol of power and innovation, but also a source of conflict and ethical dilemmas. As individuals and governments grapple with the implications of this newfound capability, the narrative delves into the personal and societal transformations that arise, exploring themes of identity, control, and the ever-blurring line between human and machine.