By late 1993, Caifanes became a three piece with the exit of Romo and Herrera. Federico Fong filled in on bass and Yann Zaragoza played keyboards. 1994's "El nervio del volcán" ("The Volcano’s Nerve"), released by BMG, showed Caifanes with a heavier, more progressive sound. Without the distractions of Romo's lively and fluid bass playing or Herrera's atmospheric keyboards, Marcovich's staccato guitar work, Alfonso's polyrythmic drumming, and Hernandez's brooding and haunting vocal style became even more prominent. “Afuera” ("Outside"), the first single, fused rock grooves with an ethnic-inspired guitar solo. “Aquí No Es Así” (“Here Is Not Like That ”), and "Ayer Me Dijo Un Ave" (“Yesterday a Bird said to me...”) became radio favorites. “Aquí No Es Así” achieved great success in Mexico and several countries of Latin-America, it became the last massive hit of the band, shortly before their breakup, and its music video, directed by Carlos Marcovich (Alejandro's brother, who also directed "Afuera") tells the history of the Spanish conquest of Mexico and the Aztec Empire in just one shot.