Grandpa Max takes Ben and Gwen to a music festival in Chicago to see his favorite old-time band, Shag Carpeting, but the event's interrupted by a weather-controlling robot called S.A.M (short for Sounding Annometer Metograph). Vance Vetteroy, a weatherman who created S.A.M, reprograms S.A.M to create weather rather than report it, but S.A.M gets struck by lightning and then takes on a mind of its own. S.A.M (the cloud monster) first uses water, then lightning and finally a tornado to fight his creator, and then Ben, Gwen and Grandpa Max during the Shag Carpeting concert. Ben (as Four Arms) strums on an amplified guitar to create an opposite feedback frequency to finally destroy S.A.M.
Ben: So, this means we can go to the Sumo Slammer Convention now?
Grandpa Max: Sorry. One has nothing to do with the other. Ben: But I went XLR8 to save the day! Grandpa Max: As a matter of fact, I was wondering about that. You just happened to be him when that cloud monster appeared? Ben: Uh, yeah. Why? Grandpa Max: Well, just that XLR8 could have zipped off to that convention without Gwen or me ever realizing you were gone.
Ben: Oh, you think you know everything!
(XLR8 lands on the RV's windshield) Gwen: Now that's one ugly bug on our windshield.
Grandpa Max: Hey, hey! The Shag Carpeting autograph booth! So, who wants to come to the booth with me? Ben: I'd rather brush Vilgax's teeth with my tongue than wait in line to get those fossil's autographs.
Grandpa Max: You know I've waited all summer to see Shag Carpeting. (holds up record album) Ben: Those weirdos make Wildvine look normal. Besides, who listens to records anymore anyway?