Firesong begins with Jumper restoring the life of Albard aka the Master. He tells him that Sirene, home of the Singers, has given him the duty to train Bowman. The sceane transfers to the Manth people deliberating over what action to take now that the Mastery is in ruins. After the defeat of the Master, alone and displaced, they seek a new homeland but have no real destination and very little food.

Ira Hath, descendant of Ira Manth and a great prophetess, has a vision of the Manth people's true homeland. Throughout the book the Manth people travel with only Ira's guidance, and she becomes weaker as they go, knowing she will eventually die of prophecy. The journey is rough and from the beginning they face problems. The first problem that plauges them is a bug that goes around and takes over their thoughts and turns you into a monster and your overcome by "drunkenness" as Hanno would desribe it. Sisi gets stung and though her feelings for him have already been shown, she acts on them while infected and she kisses him. Her kiss gives him the oportunity to take out the bug and heal her. The next obsticle the Manth people face is the Barra Klin. The klin raids the group and because the only warriors are Mumpo and Bowman (with his powers) and they can't do anything against the klin's slingers, the young women are taken captive and led into a canyon maze. Through quick thinking, Bo and Kess's mental connection, and an old friend that sacrifices himself, the girls are able to escape and trap the klin underground forever. Upon leaving the maze, the Manth people are out of food, water, and firewood. The begin to despair and believe that this is the end untill Kess finds a forest. The group heads in where they meet Captain Canobius, a very large man and a survivor of a "shipwreak", for he believes he's on an island. Half of the group believes they are in the homeland but Ira knows they are not. The group splits up and those following the Hath's begin to leave. Bo had been investigating unusual things and on the way out he solves what he has looking for. He relized the Captain killed his shipmates and intends on killing the Manth people. Bowman runs in to save them and the Captain commits suicide through his poisoned soup. The Manth continue on their way until Jumper comes for Bowman. Kess refuses to let Bowman go alone and makes Jumper take her with them. Jumper allows it and they go on their way. They meet up with Albard who teaches Bowman the way of the Singer and the power of Sirene.

In the end it is revealed that Kestrel is the one who is destined to give her life, having picked up Albard's teachings along the way. Bowman is in fact the Meeting place, the point at which the great evil and the great kindness of the world will annihilate one another. This is because he was once one of the Zars, the army of the Morah, and is one of the Singer people too, as he has been trained in their ways. Upon reaching the homeland, Ira's life ends, her destiny fulfilled. Kestrel, too, ends her life with all the other Singers, singing the firesong to destroy the Morah, give humanity a fresh start, and allow the Manth people to finally reach the homeland.

The epilogue set some 8 years later finds the Manth people established in their new home, with various people married and with young families. Amongst them are Bowman and Sisi, now rulers of Gang due to Sisi's birthright. The ending sees Pinto and Mumpo betrothed, and the Manth people happy at last.