Top window: Podcast episode 3 is missing, and selecting Update Podcast won't get it back.
Bottom window: Option-clicking on the disclosure triangle reveals the missing episode.
Sometimes a Podcast doesn't download completely to iTunes. It seems to be intact, but when you try to play it — and this usually happens at the most dramatic moment — it ends prematurely. The obvious solution is to delete the partial episode and then select Update Podcast (from the right-click menu) to download it again, but that doesn't work. iTunes stubbornly ignores the fresh copy on the server.
The secret is to collapse the list of episodes by clicking on the downward-pointing triangle next to the Podcast title, and then Option-click (Alt-click in Windows) on the triangle. That will expand the list of episodes and fill in the names of missing ones in a ghostly gray with a tiny Get button beside them. Click on that button to get the missing episode. You may also see episodes you didn't realize you'd missed. (For more about David Battino's work, visit www.batmosphere.com.)