Benardete's Paradox

This is an extension of Zeno's Paradox, presented by philosopher Benardete in the 1960's. Prometheus stole fire from the gods. This made Zeus very angry. He demanded that Prometheus return to the gods with the fire by 1:00. To punish Prometheus disobedience, Zeus assembled his infinite number of demons and issued the following set of orders to them: "Demon #1, if Prometheus is alive at 2:00, kill him. Demon #2, if Prometheus is alive at 1:30, kill him. Demon #3, if Prometheus is alive at 1:15, kill him..." and so on, telling each subsequent demon to kill at half the time previously mandated. Because Zeus is all-powerful, assume he can issue these outside of time. Well, as the story goes, Prometheus is dead by 2:00, and the council of gods is not happy about this. They say: "Zeus, we'll let you off the hook if you tell us which of your demons committed this murder." Zeus replies: "But none of my demons are guilty. Really, consider any one of them, and realize that he certainly could not have done it, for an infinite number of demons preceded him. Therefore it was none of my demons." Here we see the problem. Surely, Prometheus is dead, and yet for him to be so requires that there must be some first demon to kill him, of which there is not. I.e.: he is dead and by the hands of no killer. How?