The Cisco Kid rides again, this time in the person of Cesar Romero. Cisco and Pancho (Chris-Pin Martin) come to the aid of proud but ageing cattle king Pedro de Cordoba. Posing as deCordoba's nephew, our hero snoops around in search of those who'd do the old man dirt. The villain turns out to be a close relative of hitherto spotless reputation. We won't reveal the ending of Romance of the Rio Grande, though we'll plant a few hints by noting that the cast includes Patricia Morison, Ricardo Cortez, Trevor Bardette and Tom London.