This article explores how activities of Marvel's Peruvian social audience expanded and increased the emotional bonding among its participants through the movie Avengers: Endgame, which contributed to this transmedia phenomenon's success. The research involved a netnographic study of Peruvian Facebook and YouTube communities, analyzing 40 publications and the 2,000 most relevant comments. The results show that as the movie's premiere drew closer, social audience activities became was key to expanding and intensifying emotional bonding toward the story's narrative elements (characters, plots, and conflicts) and the general Marvel transmedia phenomenon.