It is 1939, and England is poised on the edge of war with Germany and her allies. It is believed that the main target of invasion from the sea will be the south coast, and the biggest threat of mass bombing raids from the sky will be in London. For this reason, children from the inner city are evacuated to the north of England where it is believed the threat from the Germans will be much more slight.
Willie Beach is scrawny and malnourished and terrified of everything, predominantly because his emotionally and physically abusive mother has made him that way. He is evacuated to a small village called Little Weirwold and finds he is to live with a man called Tom Oakley, a gruff but very kind widower in his sixties. Willie's main goal is to not get into trouble. As he is talking to Tom he cannot take his eyes away from the poker that Tom is using to stoke the fire. Fearful of being beaten with it, he almost passes out until Tom opens a window and thrusts his head out into the air. It works - but it also makes Willie vomit severely. Once he is finished his body seems more relaxed and Tom leaves him to sleep. When he wakes Tom introduces him to Sammy, his dog, and shows him his bedroom. Willie has never had a bedroom to himself and is overwhelmed by Tom's generosity. Tom opens the letter Willie's mother has sent with him and is furious that she has sent the belt she uses to beat him with along with his things.
The following day Tom discovers Willie cannot read or write and was bullied in school. He loves art but isn't allowed to paint as that is reserved for the cleverer children in his class. Tom takes him to see the doctor and is given witch hazel for the bruises and welts all over his body, Tom also orders clothes for him from the draper as well as a couple of extra things for his birthday which is in a few days time.
Willie meets a boy his own age called Zach, also an evacuee, who is living with the doctor and his wife. He arrives in time to help Tom andWillie construct their Anderson shelter in case of German attack. Unlike Willie, Zach is confident and boisterous and highly over dramatic.Willie is shocked that Zach likes him and even more surprised when he asks to come back over tomorrow. Another boy, George, also turns up and asks them to join him and the twins blackberrying. It is obvious he has been told to ask them and is not to keen on the idea but since Zach is too thick-skinned to notice and Willie is accustomed to people not wanting him along, both boys accept the invitation. Willie meets Carrie and Ginnie, identical twins his age. The five have a wonderful afternoon and make friends quickly.
When school begins Willie and Zachwalk together and meet George and the twins outside. Because of the influx of evacuees it is much more crowded than usual. Because the male teachers have been called up to fight in the war, a additional teacher called Mrs Black has come out of retirement to teach the youngest children. Willie is mortified to admit that he is illiterate but to his surprise his new friends are nothing but supportive . Willie asks Tom to teach him to read and write so he can join them in class with the rest of the children his age.
Before his first week is out, Willie is becoming happy in Little Weirwold. He is flabbergasted to receive birthday gifts from Tom and some of the other villagers and delighted when a surprise party is given by Tom that evening.He begins to grow in confidence and his reading is also improving. The friends fall into a routine of playing games thought up by Zach in which he is always the hero and George is always the villain. Willie has them all over to his room which they love and allows them to see his artwork which he has pinned up all over the walls. It is exceptionally good and they are in awe of his talent. Zach announces that Miss Thorne is producing a children's Christmas show and needs all the help she can get. Ginnie doesn't want to act but loves seeing and offers to make costumes. Carrie says she will act as does George and Willie will paint scenery. George then announces there's to be a carol service at church, boys only, which infuriates Carrie who hates the stereotypical activities open to girls. She wants to attend the academic high school in town but It has never taken girls on scholarship. The morning after his friends come over Willie realizes that for the first time,he hasn't wet the bed.
By November most evacuees have returned to London which infuriates Miss Thorne as she has to keep re-casting English test the Christmad show, "A Christmas Carol". Willie takes over as prompter after finishing the scenery and after a week knows most of the play by heart. When he is asked to fill in for a child who is not at rehearsal he turns out to be an incredibly talented actor, even impressing Zach. When it transpires that Robert, the child playing Scrooge, has returned to London, Miss Thorne gives the part to Willie. Tom also steps in to fill in for an absence when he is asked to play the organ for the carol concert. He has not played in a very long time as it reminds him of his wife, Rachel, who died when they were both young, after giving birth to their daughter,who also passed away. Tom also takes choir practice which the children enjoy.
William finally reaches the standard of reading and writing to join his friends in Miss Hartridge's class and rather than struggling actually performs very well, getting right out of ten in an English test making him tied for fourth in class. Carrie has big news also - she will be allowed to take the scholarship examination for the academic high school. Will's happy existence is then abruptly shattered when a letter arrives from his mother requiring him to return to London for a whole to take care of her whilst she is unwell. Willie dreads returning. He takes the London train and finds his mother waiting for him on the platform. He looks so different she barely recognizes him. He picks up her bag to carry it for her and she slaps him for doing something before she had told him to. She softens briefly, lets him carry the bag, and suggests a cup of tea. She is angered to see him relaxed and smiling and fears this is a threat to her authority. She is displeased that he lied about being able to write his own letters to her but he explains he learned in Weirwold. She then tells him she has a surprise of her own and that it is back at the house. The surprise is more of a shock - there is a baby in a wooden box, tape over its mouth. To learn discipline, his mother demands thru ignore her when she cries, he unpacks his rucksack and gives her the presents he has brought. She becomes progressively more angry, refusing to believe that anyone would give gifts without him begging and accusing him of stealing the artwork.She hits him across the head with a cold, heavy object and he wakes up later to find himself locked under the stairs, beaten and bloody.
Tom misses William terribly and is concerned not to have heard from him. When he has a disturbing, violent nightmare about being locked in a confined space, and thinks he hears Willie calling for him, he decides to go to London to make sure Willie is alright. He is so obviously lost when he reaches London that the fire warden takes him under his wing and whilst they wait out an air raid at the community shelter, Tom explains the situation and tells him why he is worried about Willie. The warden is from the area and knows Willie, but hasn't seen him since he was evacuated. A fat woman nearby is Mrs Beech's neighbor and offers to take them to the house. She says she has heard lots of bumping noises next door but no sign of Willie. Tom insists on visiting anyway and although the house seems empty, Sammy is scratching and whining frantically at the front door and pulling the leg of Tom's pants to try to get him to open it. The warden is anxious and asks a policeman to give permission for the door to be broken down. The vile odor inside sends them reeling and Sammy runs to a tiny door under the stairway where the smell is at its worst. They open the hole and find Willie tied to a length of copper piping, sitting in his own urine and excrement, holding a baby in his arms. Tom tells him he and Sammy are there and that they are going to the hospital with Willie. The baby is dead, and Willie is close to death himself. At the hospital Willie is treated and his sores patched up but he is being pumped full of sedatives which the nursing staff give him by force. Tom learns their plan is to send him to an orphanage and he hatches a plan of his own. Waiting until the shift change before wrapping Willie tightly in a blanket and carrying him to the station where they board the train for Little Weirwold. He takes him directly to see Dr Little. Will has horrendous nightmares that escalate until one night when his screams are almost primal and after that his sleep is calmer and without nightmares. Tom decides to take Willie to the sea to convalesce. Joined by Zach, they find a charming bed and breakfast owned by a middle-aged widow called Mes Clarence. They spend their days riding bicycles, exploring the little shops,and teaching Will to swim. When they return they are greeted by an ebullient Carrie who has been accepted into the high school.
The last weekend of August, the children decide to pay a visit to Spooky Cott, a big house said to be haunted. Will and Zach head one way, George and the twins the other. They hear tender, mournful music playing which scares George and the girls enough to make them leave, but egged on by Will, who is not particularly scared, Zach goes inside. They meet a young man called Geoffrey, with his left leg amputated at the knee and one of his ears missing. He was wounded in the war and is a resident at the rehabilitation home but is living at Spooky Cott because he needs some time away from other people. Geoffrey is an artist and when Will shows him a picture he has drawn Geoffrey realizes he has a great gift and offers to teach him. He is also cheered at the prospect of teaching at their school now Mrs Hartridhe has left. Will cannot wait to tell Tom the news but gets home to find that the authorities from London have caught up with them and want to put him in a smaller children's home where he can be adopted by a loving couple without a child of their own. He tells them he will always run away to come back to Tom as he is the only person on earth who loves him. Tom manages to convince them that Will would do best with him and will be adopting him as soon as the official paperwork is complete. Tom is almost as joyous as Will, as they whirl around the room like dervishes, laughing and yelling.
Zach returns to London for the weekend as his father is gravely injured by bombings. They are worried for Zach's safety when,after church, they hear a radio broadcast relaying the need that an estimated four hundred people were killed in air attacks in London's Docklands. When they hear nothing from Zach or his mother they grow more and more anxious; then the Littles, eyes red-rimmed, come by and one look at their faces is enough to tell Will that Zach is among the dead. He does not deal well with his loss,avoiding every place that reminds him of Zach and finding himself unable to paint because he feels empty inside. Carrie is also finding his loss hard to bear but Will wont talk about him, and finding her family frustrated with her new way of speaking at the "la di da" school feels very alone. Eventually Geoffrey explains that he smokes his best friend's pipe because he feels close to him again, having lost him at Dunkirk, and that by looking at Zach's things and visiting the places they went together he will in some ways have him with him even now he is gone. Will dashes to the Littles to ask if he can have Zach's bicycle which he teaches himself to ride and talks to an imaginary Zach whilst he does so.
It seems to others that Will has become a little more like Zach since his acceptance of his death. For example, Miss Thorne wants him to play Peter Pan in their upcoming show, but instead,will asks to play the flamboyant and infinitely more Zach-like Captain Hook. He is a huge success and that night, with the applause still ringing on his ears, he realizes that he is truly happy and very glad to be alive. He realizes how far he has come, and when he hangs up his jacket on the hook in the hallway only to find it is too low for him, he announces to Tom - whom he now calls Dad - that finally he is growing.