Siblings Heather and Picket Longtreader are playing their favorite game, Starseek, in a meadow by their elm-tree home. The game uses a star-shaped toy that Heather invented from sticks and a scarlet ribbon. Picket is winning their match 2-0 when Heather makes a dramatic catch, closing the score to 2-1. Heather then throws the star for what could be a deciding round. It flies erratically and gets stuck high in a dying maple tree at the edge of East Wood, an area that their father has forbidden them from entering. Heather offers to boost a reluctant Picket, who’s afraid of heights. As Picket hesitates, lightning strikes the maple, knocking both rabbits to the ground and leaving Picket unconscious. A large, flaming branch cracks off and falls directly toward them.

Heather tackles her unconscious brother, rolling them both to safety just as the burning maple limb crashes to the ground. A heavy downpour begins as they race across the meadow toward their home. Their parents and baby brother, Jacks, are waiting on the porch, and their father runs into the storm to guide them inside. Within the safety of their elm-hollow home, the family warms up by the fire. Picket is ashamed that he fainted, but his father reassures him that it’s a common weakness for rabbits. The children ask for a story, and after a moment of visible sadness, Father agrees to tell a true tale of bravery about “The Rise and Fall of King Jupiter the Great” (27).

Father tells the story of King Jupiter Goodson, a great rabbit king who lived in the Great Wood long ago. Jupiter inherited a small kingdom called the Thirty Warrens and, through his wisdom and military skill, expanded it to nearly 100 warrens. He was a humble and just ruler but also a fearsome warrior who personally defeated the wolf king Garlacks. Eventually growing tired of war, Jupiter dedicated himself to diplomacy, forging alliances and establishing an era of peace with the help of his chief ambassador, Garten Longtreader. He married and had a large, happy family. Father concludes the first part of the story by saying that “almost everyone loved him loyally” (33). Father becomes emotional and can’t continue the story, so Mother sends the children to bed. Later, Heather hears her parents singing a song that is both sad and hopeful.

Heather wakes up and overhears her parents having a hushed, worried conversation with an elderly female stranger. From the stairs, Heather hears the visitor warn that “Morbin has set his wolves on the hunt” for an object called the Green Ember (36). After waking Picket, Heather meets the guest, Lady Glen, a stern rabbit dressed in black. Lady Glen asks each sibling in turn whether they long for a king like Jupiter Goodson, and both earnestly express that desire. Satisfied with their answers, Lady Glen tells them that although Jupiter is gone, “others take up his cause, and another fills his place” (40).

Heather and Picket are sent to pick berries in West Wood while the adults continue their serious conversation. While on the path, they hear screams from the direction of their neighbor Mr. Elric’s farm. They immediately abandon their task and run for home. As they approach, they smell smoke and see a thick haze filling the sky. Upon emerging from the woods, they’re horrified to find their home engulfed in flames. The meadow is occupied by troops of black-clad wolves who wear a red diamond symbol and have a letter “M” branded on their arms. Heather drags a sobbing Picket into a nearby thicket to hide. From this cover, she sees figures fighting near the burning house and fears for her family. Picket’s cries alert five wolves, who charge directly at their hiding place.

As the wolves approach, Heather orders Picket to run to a secret cave at the Seven Mounds and not to look back. She stays behind to create a diversion, confronting two of the wolves. Their leader is a captain with a scarred face and a single red eye. The captain mocks Heather, calling her father a traitor. Seizing an opportunity, Heather pretends to be defeated before darting between her captors and escaping deeper into the thicket. In response, the wolves shoot flaming arrows into the brush, setting it ablaze. Heather flees the fire but is caught in a dense wall of smoke. As the smoke briefly parts, the red-eyed captain spots her. Disoriented, she runs blindly until the smoke finally clears, only to find herself cornered at the edge of Evergreen Row by 10 waiting wolves.

Facing certain capture, Heather charges directly at the wolf captain, Redeye, intending to attack. As Redeye draws a spear and his soldiers spread out to trap her, she hits the ground just short of the wolves, springs up, and grabs the low-hanging branches of the pine tree above his head. 

The narrative then shifts to Picket’s perspective. He successfully reaches the hidden cave. Overwhelmed with guilt, he believes that Heather has sacrificed herself to save him and that he has failed in his duty to protect his family. He looks out of the cave entrance toward the trees, resolving to find Heather, Jacks, and their parents.

Heather’s grab of the pine branches causes them to swing down, knocking back Redeye and his soldiers and giving her a chance to climb higher. She begins a desperate escape, leaping from tree to tree through Evergreen Row while wolves pursue her from the ground and in the branches. Redeye directs the chase, and archers shoot at her, with one arrow splitting the top of her ear. To evade her pursuers, she fakes a long leap to the next tree and then drops to the ground behind them. Exhausted and injured, she makes a final sprint toward the Seven Mounds, with Redeye close behind. The sight of Picket in the cave entrance gives her a final surge of strength, but when she tries to slide through the narrow opening, she gets stuck, trapped and helpless.

As Redeye moves in to kill the trapped Heather, a gray rabbit and a white rabbit launch a surprise attack. The white rabbit tackles a second wolf while the gray rabbit soars toward Heather from Redeye’s blind side. The gray rabbit kicks Heather hard in the shoulder, forcing her through the opening and into the cave. She’s knocked unconscious but is safe. The gray rabbit, who’s revealed to be their uncle Wilfred Longtreader, guards the entrance with a sword. The white rabbit threatens Redeye, calling him “Redeye Garlackson,” which causes the wolf captain to retreat. The white rabbit enters the cave and insists that they must move Heather immediately. Wilfred is too large to fit into the cave. Realizing that there’s another opening via an underground stream, Wilfred goes to find that exit point and wait for them outside.

The white rabbit, who introduces himself as Smalls, carries the unconscious Heather as Picket leads them through a labyrinth of tunnels beneath the Seven Mounds. Using his memory of the landscape and his knack for calculation, Picket navigates the confusing passages while they’re pursued by unseen creatures. They eventually arrive at a junction with three identical tunnels, and Picket is unable to determine the correct path. With their pursuers closing in, Smalls makes a guess and pushes Picket into the middle passage. They slide down a steep, watery chute that extinguishes their last torch, plunging them into total darkness. The tunnel abruptly ends, launching them into the air.

Picket lands in a freezing underground pool inside a vast cavern. He finds Heather, now conscious, struggling to keep an unconscious Smalls from drowning. They manage to drag Smalls, who has a head injury, to shore. Picket discovers a boat chained to the cavern wall just as their pursuers begin splashing into the water from the chute above. He hears Uncle Wilfred’s calling through a small opening in the rock wall. Wilfred is outside but can’t break through. Picket uses Smalls’s sword to sever the chain from the boat, freeing the anchor, and then feeds the chain through the opening so that Wilfred can use the anchor as a battering ram against the wall. Wilfred pulls with full force, but the wall holds. As hostile creatures crawl from the water toward them, Picket grabs the broken sword to make a hopeless final stand.