Ben, Guinevere, Sorrel, and Twigleg eat breakfast. Guinevere gently asks if Ben is an orphan. When he confirms, she says he has Firedrake and the others now. Ben is happy for their friendship but says it is different from having parents. Then Lola returns, flying her plane through Guinevere’s window. She reports that she saw no signs of Nettlebrand and Ben is relieved. But Guinevere insists she saw him. They find the professor and Firedrake to share Lola’s news. The professor suggests that everyone gather so they can try solving the djinn’s riddle.

Nettlebrand hides nearby in the river below the monastery and sends Gravelbeard to spy. Gravelbeard climbs the rocky mountainside to the monastery in time to see Ben leave for Guinevere’s room and Firedrake go to sleep in the hall. He hides in a shadowy corner and waits. Later, he sees the group emerge from the main building again, Ben carrying a moonstone, as the lama leads them away. Gravelbeard follows.

The lama leads the group past a series of buildings, and soon, Vita joins them. They reach a rocky wall, where the monastery meets the slope of the mountainside. The wall is filled with holes that the lama calls dwellings. Nearby, there are two dragon heads carved from stone.

Ben smashes the moonstone against the dragon’s head, and it shatters into splinters. A deep rumble resonates from deep in the mountainside and a figure emerges from one of the holes. He is a brownie like Sorrel, but he has four arms. Ben realizes he has 20 fingers, satisfying another part of the djinn’s riddle.

The brownie is Burr-Burr-Chan. He used to live with the dragons in the Rim of Heaven, but after Nettlebrand’s attack 150 years ago, the dragons hid in their cave. Eventually, they stopped coming out at all, turning into “pathetic, sniveling, cowardly weaklings” (399). The Dubidai, the brownies of this mountain range, carved that cave for the dragons but “never meant for them to bury themselves alive in it” (400). The Dubidai left and said they would only return if the dragons summoned them with a moonstone and asked for their help to defeat the Golden One.

Firedrake announces that the Golden One is dead, and he has come in search of a home for his community of silver dragons. Guinevere interrupts, insisting that Nettlebrand is not dead and they should be careful not to lead him to the Rim of Heaven. Burr-Burr-Chan assures her that the Rim of Heaven is difficult to find even when one knows where to look. He describes a ring of mountain peaks and a valley, with a cave so well hidden you cannot see it even standing beside it. He will lead them there as soon as the sun sets.

They return to the main hall. The lama remarks that the small shall defeat the great, giving Ben hope. Sorrel complains of the smell of mountain dwarf. A second later, they see a figure dashing away from the monastery. Guinevere says it is the dwarf she saw with Nettlebrand and Twigleg confirms he is Nettlebrand’s new armor cleaner. The professor apologizes to Guinevere for not believing her.

The monks give Ben and Sorrel warm clothes for the journey. Seeing the preparations, Lola decides to join them. The professor laments that he and his family cannot join them on this part of their adventure but will be at the monastery waiting for their return. The professor invites Ben to live with the Greenblooms if he decides not to stay with the dragons. Shocked and elated, Ben accepts the invitation.

As they take off, Burr-Burr-Chan asks what Firedrake will do if Nettlebrand successfully follows them, wondering if he will hide like the others. Firedrake vehemently refuses to ever hide again. Satisfied, Burr-Burr-Chan leads them on.

Gravelbeard scrambles down the mountainside, narrowly escaping capture. He tells Nettlebrand everything he heard, including general directions to the Rim of Heaven. Nettlebrand recognizes the description of the area and realizes he visited it before, but the cave was too well-hidden for him to see. He tells Gravelbeard to climb into his mouth so they can dive again.

Firedrake heads for the ring of white peaks in the distance. He feels strong and joyful as he reaches the end of his search. Sorrel and Burr-Burr-Chan discuss mushrooms while Twigleg and Lola hide among Ben’s clothes against the cold wind. Finally, they fly into the valley at the center of the Rim of Heaven. There is a large lake in the middle, called the Eye of the Moon, surrounded by blue flowers. Twigleg stares at the lake with horror, realizing that Nettlebrand can travel through it. They fly higher and land on a ledge overlooking the lake.

They do not see Nettlebrand but agree not to enter the hidden cave if there is any chance that he is nearby. They decide that Lola and Twigleg will fly over the lake in the plane to search for signs of Nettlebrand and distract him if he is there. When he is distracted, the others will sneak into the cave. Firedrake remarks that “the world will belong to small people one of these days” (427) and Lola agrees.

Lola and Twigleg fly over the lake. At first, they find no sign of Nettlebrand, then Twigleg sees a shadow in the water and senses that Nettlebrand is there. Lola flies lower over the water in time to see Gravelbeard running along a bank. Lola drops low and Twigleg grabs the dwarf, but Nettlebrand’s head erupts out of the water and snatches him with his teeth.

Twigleg shouts for Lola to fly away. Lola zips around Nettlebrand’s head, while Twigleg hunches in his seat, afraid to be seen. Firedrake and the others disappear into the hidden cave. Lola flies the plane back to the ledge to hide again. Nettlebrand gives up and disappears beneath the lake’s surface.

With Nettlebrand distracted, Burr-Burr-Chan leads the others to a secret entrance to a cave. They enter a dark tunnel that leads into the mountain, the path faintly illuminated by moonstone walls. Burr-Burr-Chan explains that the Dubidai made the walls out of moonstone. It absorbs moonlight and dragon-fire.

Firedrake knows they cannot fight humans, but they can and should fight Nettlebrand. Sorrel objects, saying that Nettlebrand is too large and powerful for Firedrake to fight, but Burr-Burr-Chan suggests that someone small and clever would have the advantage.

They reach a large cavern filled with stalagmites. Firedrake breathes fire to light the moonstone walls and everything glows. There is no sign of other dragons. Then a figure appears from an adjacent tunnel. Sorrel tells Ben it is a she-dragon because her horns are straight instead of curved like Firedrake’s.

The dragon is fearful until she realizes that Firedrake is not gold. Then she sees Ben and realizes that the legendary dragon rider has returned. Her name is Maia. She is the only one left out of 23 dragons because she was the only one brave enough to fly at night. She warned the others that lack of moonlight would eventually be more dangerous than the Golden One, but they did not listen. Deprived of moonlight, the other dragons stopped moving and turned to stone. The group looks around and realizes with horror that among the stalagmites are stone dragons.

Maia agrees to help Firedrake fight Nettlebrand, but she is afraid there is not much the two of them can do. Insulted, Sorrel explains that there are far more than two. There are seven of them, including Twigleg and Lola waiting outside.

Sitting inside Nettlebrand’s stomach, Gravelbeard refuses to come out. Beside him is “the golden casket that [holds] Nettlebrand’s heart” (448). He says he is tired of being swallowed and will not come out unless Nettlebrand promises not to swallow him again. Nettlebrand complains that the strange plane carrying Twigleg escaped, and he needs Gravelbeard to find him. Gravelbeard finally crawls out, muttering that he understands now why Twigleg ran away.