The story deals with Harvey Cutter, a hunter, who travels to MioceneItaly to capture specimens of primates for the San DiegoCenozoic Zoo. Cutter has difficulty finding the best lure for his last specimen, until he hits on the best idea on how to catch his prey.
He uses creme-filled chocolate sandwich cookies, i.e. Oreos. The story ends on a pun by revealing just what Cutter was trying to catch: Oreopithecus.
When the story was collected in Departures, Turtledove wrote in his introduction to the story that the Oreo-Oreopithecus pun was made by his wife Laura Frankos, and then he wrote a story around it.