Mr. Beaver meets Roz at the pond to plan a lodge for Roz and Brightbill. Roz asks for a home that is large enough for both of them, comfortable, safe, and near the pond. Because Roz does not know how long she will live there, Mr. Beaver decides the structure should be strong and spacious, with room for future guests and a garden that might help Roz attract neighbors.

Roz and Mr. Beaver consider how to keep the lodge warm. Since beaver lodges are heated by bodies and Roz cannot provide that kind of warmth, Roz remembers sparks from the mountain and suggests using fire. Mr. Beaver is nervous because he knows fire as a destructive force, but Roz promises to be careful.

Mr. Beaver chooses a dense patch of forest jutting into the pond as the building site. He directs the work while Roz uses her strength to clear trees and shrubs much faster than he can. By sunset, they have enough wood, and Mr. Beaver leaves Roz with extra tasks for the night: remove stumps, gather flat stones, and level the ground.

The next morning, Mr. Beaver finds that Roz has completed every task and has also taught herself to make a small campfire to keep Brightbill warm. Roz explains how striking stones together creates sparks that can ignite dry leaves and wood, and that water can put the fire out. Mr. Beaver is amazed to see fire controlled and useful rather than raging through the forest.

Roz and Mr. Beaver continue building with trenches, stones, logs, mud, and leaves while other animals watch. The finished lodge is a large dome with a stone door, one round room, a central fire pit, a vent of branches, moss-covered stone benches, and storage for Brightbill’s food and water.

Mr. Beaver says the new home deserves a name, and Roz decides to call it the Nest because it is for Brightbill, and birds live in nests. Mr. Beaver approves the name, Brightbill repeats it happily, and Mr. Beaver leaves after advising Roz to ask Tawny the doe about starting a garden.