In 1956, the couple moves back to Mexico. Altolaguirre works on an edition of his Poesías completas (complete poems), and undertakes new projects for the theater and cinema. He puts most of his energies in El cantar de los cantares (Song of songs), an ambitious film that is shown out of competition at the San Sebastián Film Festival in July. After the screening of the film, Gómez Mena and Altolaguirre are traveling to Madrid by car when they have an accident on the road to Burgos. Gómez Mena is killed on the spot, and Altolaguirre dies three days later, on July 26, 1959.