Cole, his brother, Hunter, and friends Dalton and Jace enter Necronum, the fourth of the five kingdoms of the Outskirts. Children from Earth are often kidnapped and brought to the Outskirts to serve as slaves, and the evil High Shaper particularly needs children who display magical ability. Cole is dedicated to helping the High Shaper’s daughter Princess Mira rebel against him, while also trying to find his friend and the girl he likes, Jenna, who was kidnapped from Arizona and brought to the Outskirts along with Cole.
In Necronum, the magic users are called weavers, and they work with echoes, which are ghosts. Cole and the other boys visit the Seven-Cornered Shrine to ask the echoes about the location of Mira’s two sisters, Honor and Destiny. At the shrine, Cole makes a donation to a beggar, but the beggar turns out to be an echo named Sando, who offers to help him.
Sando warns Cole that the powerful evil echo Nazeem is trying to find a way to leave the echolands and return to Necronum. Sando offers to give Cole information about where Destiny has been, in exchange for a favor. Cole accepts, promising to deliver a silver ring to the person of Sando’s choosing, and Sando tells him that Destiny has been to the Cave of Memory in recent months.
The Cave of Memory is impossible for echoes to enter. When a living person enters the cave, they leave behind an imprint of themselves, mimicking their personality. Cole can question Destiny’s imprint and learn where she went.
Through the silver ring, Sando communicates with Cole and tells him to escape northward with his friends because Enforcers from the High Shaper are coming to arrest them. The group decides to split up, Mira with her adult guardian Joe, Dalton with Jace, and Cole with Hunter. They intend to meet at the town of Rincomere later.
The Enforcers arrive, and Cole has to face them alone. He asks them about their true loyalty—whether it’s to the High Shaper or to his right-hand man, Owandell, who secretly supports Nazeem and wants to bring down the High Shaper. The Enforcers still think they’re following the High Shaper’s will, but when they try to grab Cole, a large, fierce horse runs up and fights them, kicking every Enforcer until they’re all incapacitated. The mysterious horse then runs away.
Cole and Hunter meet Mira and Joe in Rincomere, and everyone decides that Cole should be the one to enter the Cave of Memory and speak to Destiny’s imprint. The imprint tells him about a prison in Necronum called Gamat Rue where an evil echo named Nandavi holds a prisoner named Ragio, who Destiny went to find.
After exiting the cave, Cole tells his friends what Destiny's imprint said. He, Hunter, Dalton, Jace, Mira and Joe all travel toward Gamat Rue. Following Sando’s ghostly advice, Cole takes his friends on a long trail where they stop at the cottage of Tuto, a weaver and a member of the Unseen. The Unseen, including Joe, are radicals who support the Pemberton princesses and want to bring down the High Shaper’s regime.
Tuto volunteers to guide them to Gamat Rue, which he warns is a haunted ground populated with echoes that could physically harm or even kill them. Once they reach Gamat Rue, Sando orders Cole to give his silver ring to Jace. Cole does so, which ends Sando’s bargain not to harm Cole or his friends.
Sando materializes in the flesh, and with Tuto’s help, betrays Cole and binds all of the travelers with magic, intending to take them to Nandavi in the echolands. Mira makes a deal with Sando — that she will come to the echolands willingly if Sando lets Cole go free. Mira, Joe and Jace fall to the ground unconscious as Hunter physically fights against Sando.
Sando vanishes to the echolands, leaving behind Mira, Jace and Joe’s lifeless bodies, which Hunter says are enduring a type of death called longsleep because Sando has taken their lifesparks. Hunter weaves some magic to protect the bodies from decay until they can restore their lifesparks. Cole blames himself for entering into an unwise bargain with Sando and bringing about the disaster.
Hunter is a skilled weaver and briefly sends his lifespark to the echolands, where he contacts Ragio and finds out that Destiny escaped Gamat Rue but that her power, which her father had stolen from her, is being collected elsewhere in the echolands. Destiny went to a place called the Temple of the Robust Sky where she will be able to cross into the echolands and regain her power. Hunter cannot return to the echolands because Nandavi is holding his echo hostage and could easily kill him, so the boys decide to send Dalton to find their kidnapped friend Jenna in Necronum at the Temple of the Still Water and tell her that she has a hope of being rescued. Hunter will protect the deceased bodies of Mira, Jace and Joe; Cole will travel to the Temple of the Robust Sky to find Destiny.
Cole talks to the Temple of the Robust Sky’s prelate, Elana, a member of the Unseen. Elana takes him to a secret chamber where the bodies of Destiny and her sister Honor are both resting, their lifesparks obviously gone over to the echolands. Destiny crossed over to find her power, Honor crossed to rescue Destiny, and both of them ended up in longsleep.
Elana helps Cole disconnect his lifespark from his body so that he can cross to the echolands and rescue Destiny. In the echolands, she warns Cole to beware of the call of the Other, a beautiful strain of music calling echoes to the next phase of afterlife. The Other’s music is strongest near channels, river-like slipstreams of ether, and faintest at the temples in Necronum.
Elana is shocked to learn that Cole is heading to Deepwell in the Hundred Forests, a place ruled by Nazeem. Because echoes can sense lies and Cole needs a reason to travel to the Hundred Forests, Elana commissions Cole as an errand boy for the temple, delivering a message to Lottie Natt of the Sweet Channel Charnel House. She says Lottie will give him advice on how to find Deepwell. She also warns him that every person, place and thing in the echolands exudes subtle music and that in most cases music that makes him uncomfortable will mean he has found a person, place or thing he should avoid.
A female echo named Keko starts following Cole, offering him assistance. Her music is unsettling, and she even attacks him by freezing him with magic, but he manages to escape her. As he travels, she and some associates of hers block his path on a bridge across a slipstream of ether.
Before Keko and her friends capture Cole, the mysterious horse that saved him in Necronum appears again in the echolands, knocking most of Cole’s enemies into the slipstream. The horse bends down so that Cole can mount her, then they ride away at a gallop toward the Hundred Forests where the horse, nicknamed Thunder, drops him off at a giant building called the Hall of Glory.
Cole meets a man named Harvan Kane, who used to know Owandell. Nazeem taught Owandell shapecraft, and Owandell used shapecraft to take the princesses’ powers and give them to the High Shaper. Harvan died before he could stop Owandell, so now he wants to help Cole. Harvan and his heroic friends Winston, Ferrin and Drake accompany Cole to the Sweet Channel Charnel House, a disposal zone for dead echoes whose lifesparks have crossed over to the Other.
At the charnel house, Lottie weaves magical shrouds for Cole and his four friends, which disguise their energy and make them appear to be shapecrafters serving Nazeem, so they can infiltrate the shapecrafter-ridden Deepwell. In Deepwell, they rescue Honor’s servant Desmond, who says that Honor is in the echolands’ version of Gamat Rue with Nandavi. They split up, Desmond, Ferrin and Drake heading to Gamat Rue to rescue Honor, and Cole, Harvan and Winston travelling to the Fallen Temple to find Destiny.
In the Deadlands, a place swarming with dead echoes who haven’t entered a slipstream, they encounter a bright echo of Destiny’ aunt, Prescia Demorri, Grand Shaper of Necronum. She warns them that Destiny is by far the most powerful of Harmony’s daughters and that her prophetic gift is frightening. Prescia says that when the shapecrafters attempted to separate Destiny’s power from her, the power went into a horse and became the Mare, the mysterious horse that has rescued Cole twice.
Prescia thinks that Cole’s interactions with the Mare prove he’s meant to find Destiny. She sends them to the Farthest Mountain to seek counsel from She Who Stands at the Summit. Prescia gives Cole the Weaver’s Beacon, a magic lantern that will guide him to the mountain.
After weeks of travel, they reach the Farthest Mountain. Flying shapecrafters, including Sando, arrive to stop them. Harvan and Winston fight the shapecrafters while the lantern leads Cole up the mountain. She Who Stands at the Summit tells Cole that Winston’s lifespark passed on and that the shapecrafters captured Harvan. She says that she was one of the original creators of the Outskirts who bound Nazeem, who is actually a torivor named Ramarro, an alien being from another dimension.
She sends Cole to the Warden of the Light. On the way, he travels through the Pass of Visions and encounters imaginary enemies who keep trying to engage him in fights, but Cole evades them. He discovers that the Warden of the Light is really Dandalus, founder of the Outskirts, whom Cole met once before in a vision. Dandalus offers to transport Cole directly out of the Outskirts and back to Arizona, but Cole can’t accept the offer since it would mean leaving behind Dalton, Jenna and Hunter, who also need to get home.
Dandalus reveals that the Outskirts were originally all echolands. Deceased people in the echolands used magic to build the Outskirts, a real place shaped by people in the afterlife. They brought in humans from Earth to inhabit the world and divided it into Five Kingdoms dominated by different types of magic so the humans’ magical abilities couldn’t destroy the Outskirts. He says if Nazeem gets free and returns to Necronum, his shapecraft will tear apart the Outskirts, leaving only the echolands. Dandalus introduces Cole to Destiny, who has been safe with Dandalus all along.
Cole and Destiny leave Dandalus and are immediately attacked by Sando and a group of shapecrafters. Destiny jumps in a slipstream to escape, and Cole dives in after to rescue her. Cole pushes Destiny upward, where Sando grabs her and pulls her out of the slipstream.
As Cole resists the call of the Other and the pull of the current, he can feel his long-dormant magic waking up. He takes out his formerly useless Jumping Sword and uses his magic to activate it and jump out of the slipstream. Thunder arrives to give Cole a ride to Destiny. Thunder can ride through the echolands or Necronum, and to Cole’s surprise, Thunder takes Cole to visit Jenna, who is working as a servant at the Temple of the Still Water.
Cole reassures her that Dalton is going to try to rescue her, and then Thunder takes him back to the echolands to meet Callista, the deceased Grand Shaper of Elloweer. Using his raw magical power, he imbues Callista with the ability to use her powers again.
Callista and Cole ride to Gamat Rue, where Cole magically breaks down the gate of the fortress. Inside, Cole frees Harvan and reignites Harvan’s magical power just as he did for Callista. He finds and frees Jace and Joe, and they all travel together to a cavern in Gamat Rue where the echomancer Nandavi is holding Prescia, Honor, Desmond and Drake captive. Cole pours his power into his magical lantern, and the brilliant light of it distracts Nandavi and her shapecrafters, which allows Cole’s friends to attack them.
Before Cole can rescue Honor, Sando kidnaps her and teleports her to Necronum. Prescia teleports Cole to Necronum, where he uses his Jumping Sword to stab Sando, killing his echo. Prescia transports Honor and Cole back to Gamat Rue, where their friends have completely subdued the shapecrafters.
Together, all of Cole’s allies ride to the Fallen Temple. Inside, Nazeem, now referred to by his real name, Ramarro, captures them and offers to let Cole join him. When Cole refuses, Ramarro begins siphoning power from Thunder, trying to grow powerful enough to break free from the Fallen Temple and come back to life.
Cole uses a magical rope to lasso a piece of the powerful Founding Stone away from Ramarro before he can use it. Dandalus appears to Cole in a vision, and with Cole’s help, works magic to send Ramarro not into Necronum where he can run free, but to an inescapable holding facility in the kingdom of Creon, called the Void.
Ramarro disappears, and Cole and his friends find Mira, free her and reunite her with Destiny. Then Destiny is able to reabsorb her original power. Mira, Honor, Destiny, Cole and Jace all touch the fragment of the Founding Stone to meet the vision of Dandalus again. He says that Enforcers have kidnapped most of their bodies, so they should leave the echolands as soon as possible. Cole returns to his physical body, which is tied up and imprisoned, but fortunately he can feel his raw power still alive and functioning within him.