The Changelings

Eleven-year-old Izzy Doyle resents her family's move to Everton, a tiny rural town where they have inherited the house of her deceased paternal grandmother, Jean. While her cheerful seven-year-old sister, Hen, adjusts easily, Izzy finds the place isolating. At the local grocery store, a cashier insists their neighbor, Marian Malloy, is a witch who watches for fairies. Izzy spies on Marian and notices small towers of stacked stones with pressed leaves arranged around her yard. That evening, Dublin, the family's black Labrador, barks at something outside, and Izzy discovers an identical tower in her own yard.

The next morning, a sweet, sad flute melody drifts from the forest. Hen appears entranced and skips into the woods, ignoring Izzy's calls. Izzy chases her but cannot close the distance, trips, and strikes her head on a rock. She wakes on Marian's sofa. Marian found her unconscious in the woods and brought her home. She explains that Grandma Jean pushed the family away not from coldness but to protect them. When Izzy hums the melody, Marian turns pale and begins packing supplies, muttering about "the Piper." She vows to find Hen and sends Izzy home, but Izzy secretly follows her into the forest, pocketing a small blue bottle of Root Revive potion from Marian's supplies.

Marian vanishes behind a boulder. Izzy crawls through a moss-covered hole, travels through a tunnel, and emerges into a forest of oversized trees bathed in green light. The path leads to Netherbee Hall, a crumbling stone waystation, where Marian catches her. They are in Faerie, Marian explains, a magical realm separate from the human world. She shows her pointed ears: She is a Changeling, a fairy shape-shifter swapped for a human child long ago as part of the Exchange, an ancient practice overseen by a figure called the Piper, or Good Peter. The stone towers in the Doyle yard are protective wards. Marian believes the Piper took Hen to Avhalon, the fairy city, violating the Exchange's rules by not leaving a Changeling in Hen's place. Before they can act, aggressive, sentient cobwebs engulf the hall. Marian helps Izzy escape through a window but is swallowed by the webs herself, calling out a last instruction: Stay on the path.

Fleeing down the path, Izzy encounters Lug, a large, hairy Changeling trapped in a silver snare who shifts helplessly between animal forms. She unties the chain's knot and frees him. When Unglers approach, eyeless hunters with tusked snouts that track by scent, Izzy leaps off the path and rides Lug's shoulders to safety. They join Lug's companions: Dree, a translucent girl who can become a butterfly or a bird, and Selden, a sharp-witted thirteen-year-old who shifts into a wolf, stoat, or stag. All three are outcast Changelings who never fit into the human families they were placed with. Izzy reveals everything about Hen. She overhears Dree and Selden whispering that Peter works for a powerful woman named Morvanna, who seized control of Avhalon and sent Unglers to capture every Changeling she could find. The three survived only because they were on Earth during Morvanna's takeover. Selden carries deep guilt, believing he could have saved the others had he stayed. He proposes they travel to Avhalon together, using the Apple Festival as cover.

The group trades at a brownie outpost for fairy clothing and Scarlet Stairstep necklaces, mushroom beads that mask human scent from Unglers. From the Giant's Boneyard at the edge of the Edgewood forest, Izzy sees Avhalon for the first time: a city at the base of mountains, dominated by a silver castle.

At the Apple Festival, disguised as a fairy family, they watch Morvanna announce she is adopting Hen, who stands beside her dressed as a princess. Izzy hides in a sack of chestnuts carried to Morvanna's tent and witnesses the queen harvest Hen's laughter, then mix it with a Changeling heart-thread, a strand plucked from a captured Changeling's chest, to create an elixir that restores her youth. Morvanna plans to release Unglers at midnight to capture more Changelings whose hearts she needs.

Izzy slips into Hen's tent and wakes her. The sisters flee up Mount Mooring but are intercepted by Morvanna and her goblin guards. The Changelings reveal themselves and fight. Peter secretly fells a giant fir with his flute to block Morvanna's fireball, and the group escapes up the mountain.

A violent rainstorm separates the sisters from the Changelings. Tom Diffley, a kind sheep farmer and inventor with part-fairy ancestry, finds and shelters them all. Izzy tells the Changelings what she overheard about the heart-thread elixir, and the news devastates them. Soon after, goblin riders on wyverns, dragon-like flying serpents, attack Tom's farm and carry the three Changelings away in silver nets. Izzy bluffs a pursuing goblin with coffee grounds she claims are explosives. Tom reveals a forgotten tunnel under the mountain that leads to the Liadan River near Avhalon and a secret water-intake passage into the castle.

The trio travels through the tunnel, but goblins seize Tom at the river. The sisters squeeze through the water-intake grate and surface inside the castle. Izzy frees Selden from a silver net in a courtyard, and Hen leads them to a hidden stairwell Peter once showed her. Hen stays in the ballroom to rig charges of blitzing powder, an explosive substance, at three columns. Izzy and Selden climb the tower.

At the top, they find all captured Changelings woven into an enormous tapestry by Lacrimo, a six-armed weaver. Each figure is frozen in animal form, with frayed patches where Morvanna plucked heart-threads. Selden slashes the tapestry; the brass rod supporting it tears from the wall and falls on Lacrimo, killing him. Izzy applies drops of Root Revive to each woven figure, and 14 Changelings emerge, weak but alive. She sends them toward the stables.

Returning to the ballroom, Izzy finds Morvanna and Peter holding Hen. Hen signals that the charges are ready. Izzy attacks Morvanna's hand to free Hen, who lights the trail. The explosion collapses columns and buries the passage under rubble. Morvanna blasts the debris clear with magic. Selden, who stayed behind, attacks as a leopard but is wounded. Peter urges Izzy to create a diversion so he can retrieve his dropped flute. When she protests she is powerless, Peter reveals that Izzy is a Changeling: Eleven years ago, he took an orphaned fairy infant to Earth, rounded her ears with his flute, and exchanged her for the Doyle newborn, who had not survived the night. Izzy recalls the foxlike stealth and other uncanny moments throughout her life and realizes they were real Changes, actual shapeshifts into other forms.

Izzy runs at Morvanna and instinctively takes on the queen's Likeness, a Changeling power to temporarily mimic another's appearance, projecting Morvanna's youthful self back at her. The aged, power-depleted queen is transfixed by the reflection of the youth she has lost and drops her dagger. When Morvanna snaps out of her trance and lunges, Izzy drops the disguise and ducks below the window ledge. Morvanna's momentum carries her through the opening; she grabs Izzy's collar, but Marian catches Izzy by the ankles. Dublin barks nearby. Morvanna falls to her death.

Izzy wakes two days later. Marian explains that Dublin followed Izzy to Netherbee Hall, enabling Marian to escape the cobwebs and travel to Avhalon. All 18 Changelings are safe. Marian reveals that Morvanna was the real human Marian Malloy, the child she was originally exchanged for, who returned to Faerie, studied dark magic, and stole Changeling power to restore her youth.

The Changelings invite Izzy to stay, but Hen tearfully fears Izzy will forget her. Izzy realizes her heart pulls her home and announces she will return to Earth with Hen. Marian stays behind to care for the Changelings. Peter escorts the sisters toward the Edgewood. Dree gives Izzy a jar of honey with a note from Selden: "Do not forgit us." Izzy takes Hen's hand and faces the distant green line of the Edgewood, ready to go home.