Nestor says that he hears hoofbeats and hopes that that sound indicates a successful return for Odysseus and Diomedes, driving horses off from the Trojans (after all, they did not leave with horses). That a return with horses is interpreted as success for what was originally a spying mission is another indicator of the thematic association between horse stealing and night themes in general. See “The Poetics of Ambush” for more on how these themes are associated within the epic tradition.