Ghost Circles is the seventh book in the Bone series. It collects issues 38-43 of Jeff Smith's self-published Bone comic book series, and marks the beginning of the third and final part of the saga, entitled Harvest. The book was published by Cartoon Books in black-and-white in 2001 and in color by Scholastic Press in 2008.
At the besieged fortress of Old Man's Cave, the Headmaster of the Veni Yan summons Wendell, the village tinsmith and explains how he believes the current unrest is not due to the Bones. He shows a medallion bearing the Harvestar family crest; a crown with a star above it. Thorn, he explains, may in fact be the "one who bears the star" The Hooded One has been seeking. Just then, the mountain erupts as the Lord of the Locusts stirs beneath it. The armies massed outside the fortress begin their attack.
The Bones, Thorn and Gran'ma Ben flee the collapsing mountain. Fone Bone leads them to the tunnel he used to escape from Roque Ja. As they descend through the tunnel, Fone warns everyone that they will probably start hallucinating again, just as they did the last time they passed through there. Sure enough, Fone and Phoney become Ishmael and Captain Ahab from Fone's favorite book, Moby-Dick. They stagger on to the tunnel exit and find the valley on the other side turned into a wasteland, covered in ash and every tree flattened.
The Bones, Thorn and Gran'ma Ben make their way across the devastated valley. Thorn leads them as she is the only one who can see and avoid the Ghost Circles, invisible pockets of unreality where nothing can live, and that separate the true, intact valley from the illusory wasteland. She and Fone brush the periphery of one, and are momentarily transported back into the forest as it stood before the devastation of the valley. Thorn explains that she can survive it, and maybe even undo the spell, because she tore off a piece of the Lord of the Locust's soul when it tried to possess her, thus inheriting some of its power. Meanwhile, the Lord of the Locusts forgives Briar for her mistake, ressurects her again, and orders her to retrieve Thorn.
Thorn and Gran'ma Ben remain undecided whether to return to Old Man's Cave or press on to the old capital, Atheia. A troop of Rat Creatures makes that decision for them, blocking the route to Old Man's Cave. A scout party of Rat Creatures discovers their camp and Thorn and Fone get separated from the others. As Ben fights off some of the Rat Creatures, a familiar face appears among them; Bartleby, the Rat Creature cub Smiley adopted has returned! Meanwhile Thorn and Fone discover Briar is the one leading the Rat Creatures to them. She reveals to Fone Bone that he too has a piece of the Lord of the Locusts' soul inside him (a result of his and Thorn's stumbling into a Ghost Circle). Briar is about to kill Thorn, who is no longer necessary to her plans, when Smiley and Bartleby come charging to the rescue.
Fleeing the Rat Creature army on the back of Bartleby, Thorn guides the party to safety through a dense field of Ghost Circles; the pursuing Rat Creatures, unable to see the deadly pockets of evil power, are vaporised. The party continues on towards Atheia.
Meanwhile, at Old Man's Cave, the villagers and the Veni Yan pick up the pieces after the attack. Lucius Down is badly wounded. While speaking to Wendell, Lucius blearily asks his friend if Jon is there. Wendell replies that he's fine, and not to think about that right now. Lucius doesn't buy it, asking Wendell why he won't look him in the eye, and then realization dawns, and Lucius murmers, "No. Not Jonathan..." (Jon's death is confirmed at a later time, when Wendell says something about him resting in peace, although the causes are not specified.) The Headmaster of the Veni Yan questions Lucius on Thorn and Ben's whereabouts, and place him under guard for betraying the Queen.
The party is growing weaker and hungrier on the long journey to Atheia, when Bartleby suddenly runs towards Fone Bone, shouting that Smiley has fallen down. He then informs Fone that Smiley is weak from hunger, and when Fone points out that he rationed all the 'stale, bread-thingies,' in his backpack, the young rat creature admits that Smiley refused to eat his rations and gave them to him(Bartleby), instead. Phoney, catching up with Fone, then sees that his cousin has collapsed, and, in one of the rare instances where he openly cares about something other than money, tells Thorn to find them some food, quickly, before the situation worsens, reasoning that she is their best hope, since she found water before. Thorn points out that underground springs survived the volcanic eruption, providing the water, but that any food that wasn't inside a ghost circle will have been destroyed. Phoney's reply is, "Then go inside a ghost circle! This is an emergency!" Thorn initially brushes this off as a crazy idea, until Fone points out that it could work, if he went with her and they held hands like last time. Although Gran'ma Ben argues that it isn't safe, and that they are in Pawa, which has gone over to the locusts, Thorn states, firmly, that they all need to eat, and she and Fone step carefully into one of the circles to look for food. They find a Ghost Circle that leads to a farm, where they collect some apples. As they make to leave, they hear the voices of the farmers and their families begging Thorn for help. The voices also pass on a message from Thorn's late mother: “Seek the Crown of Horns”. The party continues towards Atheia, but must first pass through Tanen Gard, the sacred burial ground of the Dragons and a place where anyone other than Dragons are forbidden to tread, under penalty of death.
At Old Man's Cave, Wendell questions Lucius about his supposed betrayal of the Queen, and asks why he was found in the arms of Briar just before the attack. Lucius tells of how, long ago, he was a guard at the Royal Palace and fell in love with both Briar and her sister Rose Harvester, but he chose Briar instead. He decides the time has come to leave Old Man's Cave, and asks Wendell to gather the other villagers and release him from custody.
With the piece of the Locust inside her, Thorn grows weaker by the minute. With Fone and Gran'ma Ben carrying Thorn, the party makes its way gingerly through Daren Gard, ever wary of rousing the Dragons. A bottomless pit crossed only by a steep and narrow rock bridge lies ahead. As they clamber to safety, Thorn begins to revive, the purity of the sacred ground healing her. They soon reach the ridge and find the valley beyond clear of the devastation of the Ghost Circles. The presence of Prayer Stones, idols left by Atheians for the Dragons, shows that the Old Kingdom is still alive. As they make their way towards the city of Atheia, a small, lone Locust is seen resting on one of the prayer stones.
At Old Man's Cave the villagers demand of the Veni Yan that they release Lucius, planning to head for the Old Kingdom themselves. The Veni Yan initially try to stop them, but a heartfelt speech from Lucius convinces them to accompany his party. It is at this time the veni-yan take off their hoods, indicating that they too want the old kingdom back, hence they do not need to go into hiding, or underground.