Lucy explains that she witnessed everything through the kitchen window after being awakened by Mr. Gladstone’s shouts. Emma claimed that she only came outside because Harry was in the garden, but Lucy recognized the lie because Emma curls her hair around her forefinger when lying. Stella introduces herself and Tom, saying that they need to rescue Jack immediately. When Lucy questions their plan, Tom produces the key. Stella makes Lucy promise to return home afterward and not follow them, saying that Emma will explain everything.

They enter the house quietly. Lucy leads them to a cellar door in the pantry floor, explaining that Crawley beat Jack three times, tied him up, and left him with the rats until the police arrive at dawn. They open the heavy door, and Stella shines her torch down to reveal Jack bound and gagged at the foot of wooden steps. Lucy marvels at the torch, which Tom claims is from Australia. Tom descends and removes Jack’s gag. Unable to untie the knots, Tom panics until Lucy returns with an enormous kitchen knife. Stella carefully cuts Jack’s hands free, and then Jack swiftly cuts his own legs free.

As they climb back up, a child holding a candle appears in the doorway. Stella squeals, thinking that it’s Emma, but Sophie steps into view. After a tense silence, Lucy asks what Sophie is doing awake. Sophie studies each of them, smiles broadly, and then yells for Crawley and her father. The house erupts in chaos. The children flee, dropping the key as they run.

Tom, Jack, and Stella race across the lawn toward The Island. Stella glimpses moles circling near the trees but trips and falls. Crawley seizes her around the waist, his grip tightening painfully. Her iPhone digs into her stomach through her jeans pocket. The others run back. Emma emerges from the shadows in her nightgown, accusing Crawley of being the real thief who stole their silver and her mother’s money. As Crawley’s grip loosens, Stella secretly activates her phone’s recording function. Crawley snarls that even if he had been stealing the silver, no one would believe them, and he tells them to keep quiet for their own good.

Mr. Gladstone bursts through the bushes, demanding an explanation. Crawley releases Stella and lies, claiming that Jack fought back and threatened him with a knife. Emma insists that Crawley is lying and is the true thief who also framed Jacob. Mrs. Gladstone and Sophie arrive with two policemen. Emma produces a cloth bundle containing stolen silver items. Mr. Gladstone recognizes a pillbox, salt cellar, and jug but notes the missing coin purse. Emma explains that Harry found the items buried where Crawley hid them. Crawley denies everything and continues blaming Jack. Mr. Gladstone says that the silver alone is insufficient proof.

As Crawley smiles, Stella steps forward with her iPhone and plays his recorded confession. Everyone is stunned by the disembodied voice. Lucy asks how Crawley is inside the box. Emma gives Stella a triumphant smile while one policeman scribbles notes. Crawley mutters in bewilderment and backs into the second policeman’s grip. Mr. Gladstone vows to make amends to Jacob. He looks for Jack, but he has slipped away. Mr. Gladstone orders the police to find Jack and take him home. Emma explains the iPhone by loudly fabricating a story about Lucy’s uncle’s machine from Australia, purposefully curling her hair to signal the lie. Lucy understands, plays along, and leads Tom and Stella away as her cousins.

Out of sight, Jack whispers that the moles danced again and that they must leave. Stella tells a disappointed Lucy that they’re going home. She removes her friendship bracelet and gives it to Lucy for Emma, explaining that it means friends stay connected wherever they are. Jack insists on rowing them back despite his injured back. They pull the boat under the tree, and Jack thanks them for saving him and his father. He shakes Tom’s hand, telling him to keep digging because he never knows what he might find. Stella gives Jack her orange torch as a gift.

Tom and Stella ascend the tree and enter the tunnel. Tom whispers that it’s time to go home. In their own time, as they’re crawling through the undergrowth, a twig cracks. Charlie’s shoes appear nearby. They emerge sheepishly to find Charlie sitting on the log with their lunch boxes. He remarks that it’s a good spot for a seat and hands them their boxes.

At home, Stella explains their extended absence by saying that they met two sisters who invited them in. In his room, Tom tries to picture the Gladstone dining room and looks for the carved initials, but his heart sinks when he sees that the chimney is bricked up. He steps on his “Earth Treasure Box” (76), scattering its contents. On his balcony, Stella breathes in the smell of orange-tree blossoms and plans a coded Facebook message to Hannah about time travel. Tom lies on his bed, bothered by a thought he cannot identify.

For the next week, the children search daily for the moles without success. Stella composes coded messages to Hannah while Tom grows impatient. He begins having nightmares where Crawley catches them and locks them in a broom cupboard, always with Charlie watching from a distance. Ten days after their return, Tom wakes from another nightmare and wonders if they imagined the entire adventure. He stares at three large stones that he dug up earlier that summer, and a sudden realization strikes him. He grabs his trowel, tells Stella that he found proof from the past, and races to the garden.

Tom digs frantically in a flowerbed while Stella warns that he’ll be grounded if Charlie catches him. He unearths a small, battered cloth purse that he had found and discarded at the start of the summer, now realizing that it’s Mrs. Gladstone’s stolen coin purse. He points out the barely visible initial “G” on the worn fabric, explaining that Crawley must have thrown it away after taking the money. Charlie appears and gives Tom a final warning about digging. As the gardener walks away, Stella thinks his gaze flickered when he saw the purse. She speculates that Charlie knows about the tunnel and takes Harry down it. Tom reflects on his encounters with Charlie, feeling pieces of a puzzle falling into place. Stella suggests that they visit Mrs. Moon to learn more.

The following afternoon, Tom and Stella visit Mrs. Moon, who appears alert and well. She tells them that Harry is missing but will return for lamb dinner. She mentions that Charlie lives near Kilburn, is not in the garden on Fridays, and is completely devoted to the garden. When Stella asks where Charlie thinks Harry goes, Mrs. Moon’s eyes glisten, and she offers biscuits instead. She goes inside but returns five minutes later with a vacant stare, seemingly forgetting who they are. Tom’s stomach rumbles loudly, jerking Mrs. Moon from her trance. Confused, she asks if they’re new to the garden and whether they’ve seen Harry. She then begins crying. Stella gently helps her sit and reminds her about the lamb dinner, which reorients her. Mrs. Moon says that she’s tired and sends them away.

As they leave, Harry races past them, soaking wet. They rush to The Island, but the tunnel has disappeared. The next morning, Charlie calls to say that Mrs. Moon has taken a bad turn and that a doctor has been called. Tom suspects that it’s a ploy to prevent them from talking to her, even suggesting that Charlie drugged her. Their mother confirms that Mrs. Moon is in bed and getting treatment for not eating enough. She mentions that Mrs. Moon must be nearly 100 years old. A week later, Mrs. Moon is well enough to invite them back.

On a gray and windy September day, Tom and Stella visit Mrs. Moon, who shows renewed vigor. She leads them into her sitting room, filled with dark furniture and a large portrait of her late husband, Edward Moon, hanging over the fireplace. While Mrs. Moon fetches juice, Tom wanders around examining silver-framed photographs and trinkets and then disappears into another room. Mrs. Moon returns with a trolley of tea, juice, and cookies. Tom reappears looking strangely pale and embarrassed. To Stella’s surprise, he refuses a biscuit. He bluntly asks where Harry and Charlie are.

As Mrs. Moon begins answering, Stella’s gaze fixes on an old trunk beside the old lady’s chair. Her heart races the longer she stares at it. Abruptly, she asks for more juice as a pretext to approach the trunk. Once alone, Stella rushes to the trunk and reads the worn gold lettering: “Miss S E Gladstone.” Tom joins her, and they whisper that Mrs. Moon must be Sophie Gladstone.

Mrs. Moon appears in the doorway with a strange, vacant smile, saying that they have discovered her story. When Stella asks if her real name is Sophie Gladstone, Mrs. Moon chuckles and gestures toward a second trunk in the far corner. Stella tearfully reads the name aloud: “Miss E M Gladstone.” Mrs. Moon confirms that she is Emma Gladstone from the time tunnel. She winks at Tom, revealing that he had already guessed after seeing a painting in her bedroom. Tom leads Stella to the bedroom, where he shows her the portrait of young Emma holding Harry that they had previously seen in the Gladstones’ dining room.

Back in the sitting room, Emma confirms that their adventure was real. She explains that two days after they left, she and Lucy found the tunnel and traveled to a time beyond the present day. She hints that Tom and Stella will enjoy the garden for many years but provides no details about the future. She explains that after her and Lucy’s adventure into the future, they returned after three days and got into serious trouble. No one believed their story, and her father never forgave her for the embarrassment. She began using her middle name, Margaret, to escape the notoriety. After her husband, Edward, died 20 years ago, she moved back to the garden.

Emma explains that Harry is the same dog from her childhood. He reappeared one day after she moved back, soaking wet, after she saw the moles. She believes that Harry travels between her childhood and old age to keep her from being lonely. Her memory now fails her on some days, so she doesn’t always remember the adventure. She now feels that Harry may have returned to her younger self permanently. She directs Stella to a drawer, where Stella finds the faded friendship bracelet she had sent to young Emma, kept all these years.

Tom asks about Charlie Green. Emma admits that Charlie knows about the tunnel. She told him about the tunnel after noticing Harry’s wet comings and goings, and he has been very protective of the molehills since. A grandfather clock chimes, and Emma says that her nurse is arriving and that they must leave.

The next morning, Tom and Stella’s mother tells them that Emma died peacefully during the night. Their mother mentions that Harry has not been seen for over a week. Tom feels frustrated, while Stella initially remains calm before becoming emotional. On the morning after the funeral, they watch a lonely-looking Charlie by his shed. Charlie approaches carrying a large bag, with dark circles under his eyes. He says that Emma is happy now with Harry and apologizes to Tom for being gruff, explaining that he was worried about the moles because they were important to Emma and Harry. Tom’s anger toward Charlie vanishes, and he smiles back. Charlie tells them that their secret is safe with him, winks, and departs.

Later, their mother gives them a small brown packet that Charlie left. Tom tears it open, and Stella’s battered orange torch falls out. Inside is a note from “Charles Green.” The note explains that his father became known as “Flash Jack” because of the torch and worked at the garden, as did his grandfather. Charlie writes that he helped Harry travel through the tunnel for Emma. His time at the garden is finished, and he is leaving for work closer to home. Tom gasps that Charlie is Jack’s son and races outside yelling for him, but he is gone. Stella reflects that Charlie was kind, just as Jack would have been.

Back inside, Tom announces that when he’s older, he will buy their apartment and the whole house and restore it to how it was in the past. He grins at Stella and draws the letter “T” in the air. Stella grins back, knowing that Tom will accomplish it.