magazines, including Hora Cero Semanal (weekly), Hora Cero Mensual (monthly), and Frontera Mensual (monthly). In 1958 he started writing El Eternauta, probably his most popular and critically acclaimed work. The strip, with artwork by Francisco Solano López, told the story of his meeting with a time traveler, who had already lived over 100 lives and has journeyed to the past to warn the protagonist of a future catastrophe. The strip was published in Hora Cero over 106 weekly episodes and was a massive success. His publishing house closed five years later due to a combination of the economic crisis sweeping Argentina in the 1960s, foreign competition, and the exodus of Argentine comic artists to Europe. Oesterheld continued writing for other magazines such as Zig-Zag. His work slowly acquired a greater political emphasis. His 1968 biography of Ernesto 'Che' Guevara, a year after Che's death, was removed from circulation by the government and the originals destroyed. In 1970 he wrote a scathing critical biography of Evita Peron, dedicated to Che Guevara. In 1973 he published 450 Years of War Against Imperialism. During the military government of the 1970s, Oesterheld is believed to have joined, following his four daughters, a leftist guerrilla group, the Montoneros. His story El Eternauta, Part II (1976) described a futuristic Argentina under a dictatorship. In 1976 Oesterheld disappeared. He was last recorded as seen alive in late 1977 or early 1978. His family believed he was among the tens of thousands to have disappeared and been killed by the government. In 1977 his daughters, Diana (23), Beatriz (19), Estela (25) and Marina (18), were arrested by the Argentine armed forces in La Plata. None were seen again, and they were all presumed dead. His daughters' husbands also disappeared (desaparecidos). One grandson, Martín, was born in captivity. Oesterheld's widow, Elsa Sánchez, learned about the boy and recovered him from government custody, although she never saw her daughter again. She raised Martin. A second grandson, Fernando, born earlier, was raised by his paternal grandparents. Elsa Sánchez participated in the protests of the Mothers of the Plaza de Mayo. She became one of the spokeswomen for the Grandmothers of the Plaza de Mayo, which advocates for the return of children of the "disappeared" to their birth families. When the Italian journalist Alberto Ongaro enquired about Oesterheld's disappearance in 1979, he received the reply: "We did away with him because he