AllMovie

Duel at the Rio Grande was initially titled The Sign of Zorro, but apparently the copyright police were on the job that day. Sean Flynn, son of Errol, stars in the Italian/French/Spanish coproduction as Zorro, fop by day, masked-and-caped righter of wrongs by night. Danielle De Metz costars as the lovely Spanish-California senorita whose virtue is forever in jeopardy. The younger Flynn continued pursuing an acting career into the mid-1960s, then became a freelance photojournalist. While covering the war in Vietnam, Flynn vanished without a trace in 1970, presumably captured or killed by the Vietcong.