Did You Know?
The episode's title, "And Then There Were None" is a direct reference to the Agatha Christie novel (also known as "Ten Little Indians"), with events playing out in broad brushstrokes in a similar fashion to the novel's plot (with the obvious difference being that those "murdered" in the Urusei Yatsura episode are alive and well at the end). In both, mocking notes referencing a popular nursery rhyme (in the novel, it was "Ten Little Indians", in Urusei Yatsura, it was "Who Killed Cock Robin?") were left at the scene of each killing. See more