Ernie returns home from camp.
Trivia: I notice that Ernie mentions Mr. Hooper, which ties this sketch to a specific period (i.e. pre-1983).
I have to wonder how much of this sketch was scripted. I have no way of knowing, of course, but I imagine that the original script probably ended with the line, "Oh Bert, that makes me so happy!" and I further imagine that Henson and Oz and probably Jon Stone just went to the prop room and found some items that would be interesting to Bert and put them in a suitcase and had Ernie and Bert talk about them improvisationally at the end. This is all pure conjecture on my part; it might not have happened that way at all, but that's the way I like to imagine that it went.
In any case, I do think that a sketch like this, which is light on gags and heavy on conversation, works as well as it does because Henson and Oz knew the characters so well and knew each other so well and were such good friends in reality. To me, that's one of the nicest things about Bert & Ernie sketches in particular, when you know that the friendship extended below the camera as well. I believe that authenticity is one of the key reasons for Sesame Street's unequaled success, and Bert & Ernie's relationship is an excellent example of that.
I love it when Bert & Ernie talk about feelings. It's SO important to teach kids that it's okay to talk about emotions, and boys need the message more than girls do because there's still a social stigma attached to boys and men expressing emotion. I'm not saying that it's a panacea for the ills that plague our society, but it is a vital piece to the puzzle. So it's wonderful that Bert & Ernie in particular can model that in such a positive and entertaining way, so that hopefully the message will stick.
By the way, here's some context on Bert's interest in rocks.