"Fusión" opens with a question you could only ask about someone you are completely tangled up with: "¿Dónde termina tu cuerpo y empieza el mío?" (where does your body end and mine begin?). Jorge Drexler writes about two people so close that he can no longer tell where the line between them is, and he is not sure whether it is love or desire: "¿Cuánto de esto es amor? ¿Cuánto es deseo?" (how much of this is love? how much is desire?).
The best image comes near the end of the first half: "Ya colgué mi armadura en tu portal" (I've already hung my armour at your door). Colgar la armadura is his way of saying he has stopped defending himself, and perder la mesura (to lose one's sense of moderation) admits he has gone overboard. He closes with a promise that is almost shy: "No estoy aquí de visita" (I'm not just visiting here), meaning he plans to stay, and "es para ti que está escrita esta canción" (it's for you that this song is written). Short, quiet and very sincere.