Marjory the Trash Heap's rat companions, Philo and Gunge, decide to head for their original home, although they're not completely sure they remember where it was. Marjory misses them dreadfully, but she can't help them when they're captured and enslaved by the evil Wander McMooch.
The rats are part of the magical interdependent ecosystem of Fraggle Rock. Marjory, the Fraggles' source of wisdom, only came to life when Philo and Gunge came along. If they leave her, she'll grow weaker and die.
This is the second and final appearance of the sinister, toad-like Wander McMooch, who first showed up in the second season episode "Junior Sells the Farm." It's mentioned that McMooch is an old nemesis of the Trash Heap.
This episode offers us a rare look at the world beyond the Gorgs' Garden, with a few scenes set in a swamp.