Yes, this story is only nine thousand words, when many other two-part episodes have been closer to fifteen thousand words apiece. So? A short story is not a bad story. Sometimes, a short story is actually a better story.
Framing Stories
For our purposes in talking about framing stories, we will define the story being framed as the plotlines explored directly by the narrative. To take a well-known example, look at Harry Potter. The plotlines of the character arcs, and combatting Voldemort, are the core story. A framing story could be if there were a line at the beginning or end of the books saying "based upon the diaries of Harry Potter, Wizard." Which takes us conveniently to the next set of definitions we need to supply.