I figured out what was up with 'The Guy At The End'.
OK, at the very beginning of the movie, we see two detectives- Thompson and Harcourt- discuss a letter they've gotten from a "chap on Seagull Island" who is "nutty as a fruitcake" becuase he's threatning to unleash some killer bees he's developed and kill someone. They seem willing to dismiss the whole thing.
We're then introduced to all our main characters, and watch Vicki go to Seagull Island where she can't quite figure out who the crazy beekeeper is.
After Mrs. Hargrove is murdered, we get a scene of Inspector Thompson on the telephone, apparently to a superior, saying that he's seen the article about a bee-related death on Seagull Island but didn't think anything of it. He says he'll send Harcourt over to investigate it tomorrow.
We then go back to Seagull Island where Vicki uncovers the whole thing, Manfred is killed by his own bees, and everyone is safe again.
Just as Vicki leaves the Hargrove Farm for the the final time, that's when Harcourt shows up, unaware that the whole case is already over, so the audience has a little laugh at his expense.
Got all that? Good, cause my head hurts. I'm going to bed.
~Brad