Full confession: I had forgotten completely how awesome this episode was. It is, on the surface, a "just for fun" episode. It's a very funny episode, but there are a couple of interesting things going on in it.
Up until now, the Gorgs were mostly a gang of big, bullying ogres. They had a few funny moments, but they weren't very sympathetic. For the first half of this episode, that hasn't changed an awful lot. Junior Gorg is still treated as a very intimidating threat to our Fraggle heroes, and the bulk of the plot covers his plan to destroy the Fraggles' tunnel into the Gorgs' garden once and for all.
The Fraggle temporarily left to face this attack while Gobo deals with another crisis is Red. Now, I've already talked about two Red-centric episodes and here's my chance to explain why I love her so much. Red was my favorite character by far as a child, mostly because she was awesome and funny and active and loved to swim. So in other words, I loved her surface features. Rewatching the series now, she really won me over. It's because she has all the marks of a "Strong Female Character" -- except she also gets to be insecure and vulnerable and emotional, as seen in her incredibly moving solo song here. She gets to be a character, with admirable, sympathetic, and even contemptible traits. Mind you, this is all in a show with five fantastic, well-rounded female leads and where incidental characters are more likely to be girls. Look at how freakin' easy this is, everybody!
Junior's plan to destroy the Fraggle tunnel fails for convoluted plot reasons that leave both him and Gobo badly injured and delirious. And this is where a great episode turns wonderful. The characters all sing a silly song together to keep Gobo's spirits up and it turns out Junior knows the song too. And we have an adorable flashback to Pa Gorg singing to a baby Junior. Pa and Ma both return to a ruined castle shortly thereafter and their first concern above all else is whether their son is safe. This is where we finally see another side of the Gorgs, and finally we have a real reason to sympathize with them; they're us but, uh, larger.