On steamy Pryan, Realm of Fire, never-ending sunlight and plentiful rain have created a jungle so vast that humans and elves dwell high in the trees and only dwarves live anywhere near the ground. From the treetops the aristocratic elves sell weapons to the other races, whose incessant warfare sends a steady stream of profits and essential resources skyward. Now, generations of dissent and race hatred will not heal -- not even under threat of annihilation at the hands of the legendary tytans. Armed with little more than their wits and a prophecy, elves, humans, and a dwarf must unite to try to save the world from destruction. Paithan, Caliandra and Aleatha are the three children of one of the richest elves. Caliandra runs the business, Paithan goes out on trading journeys and Aleatha lounges around, flirting with many male elves, while their father distracts himself with experiments involving rockets. Paithan goes to the nearest human town to conclude an arms deal with two humans, Roland and Rega. They are actually brother and sister but pretend to be husband and wife, and persuade Paithan to travel with them to deliver the arms to the dwarf who ordered them. They plan for Rega to seduce Paithan so that Roland can then accuse and attack him. Instead, Rega actually falls in love with Paithan, and he with her, though a series of misunderstandings delays them in acknowledging their love to each other. In the meantime, they have finally got close to dwarf lands, though they are concerned about all the reports they've heard of tytans, massive monsters, destroying settlements further north. They are captured by a dwarf, Drugar, who is the only surviving member of his tribe, and he plans to escort them back to their home and watch as they and all their loved ones die, as his did. Whenever the tytans approach people, they keep asking telepathically "Where is the citadel?" and then kill people when they cannot answer them. In the meantime, Haplo has arrived on Pryan, and couldn't work out where he was or where he needed to go until he realised that he'd appeared through Death's Gate in the centre of a massive shell world, with four suns near the centre and all life on Pryan growing on the inner surface of the sphere. He finds his way to the elf city not long after a "human wizard" arrives, who was invited by Caliandra's father, who wanted to know more about the stars in the sky and how to get up there in a rocket. The wizard is called Zifnab and talks very strangely, making references to other fictional texts including Star Wars. He is accompanied by a huge wingless dragon who serves him but also mothers him. The tytans pursue Paithan, Roland, Rega and Drugar through the forests, though they finally get back to the elf city. Haplo tries to fight the tytans and is horrified when the tytans easily break his rune magic protection, and nearly kill him. Caliandra sacrifices herself to save her siblings, and Haplo, Paithan, Aleatha, Roland, Rega and Drugar, Zifnab and the dragon, along with many other elves and some humans, flee in Haplo's ship. They fly upwards towards the stars, and keep flying towards one star until they get close enough to see that it is a citadel, in a forest. Haplo has realised that all the "stars" are citadels scattered around the inner surface of Pryan, itself a Dyson sphere. The city is surrounded by Sartan warding runes, but they are able to camp nearby. Haplo leaves the mensch and flies away, back to Death's Gate. Zifnab's dragon pretends to kill Zifnab and attack the mensch, to drive them towards the citadel, and the dwarf Drugar finally realises that the amulet he wears, which is a single Sartan rune, can be used to open the doors and let them into the citadel, where they can live, safe from the tytans.
