Plot

Young Tom Hall (Art Parkinson) and his misfit friends fight to save "Buster" the baby elephant during the German air raid bombings of Belfast, Northern Ireland in 1941.

The true story of a larger-than-life friendship. Twelve-year-old Tom (Parkinson) is the son of the zoo veterinarian at Belfast Zoo. As the bombs fall on Northern Ireland, during World War II, Tom's dad is drafted into the British army. With the animals' safety at stake, Tom must find a hiding place for the zoo's new addition: a baby elephant named Buster. Tom enlists his best friend, Pete (O'Reilly), and sensitive classmate Jane (Flain) to help him hide Buster.

In this fact-based story set in 1941 Belfast, Northern Ireland, numerous people follow as Buster the Elephant is delivered to the city's zoo. Charlie the security guard says no one is allowed in until the zoo actually opens. Tom, however, stays around. His father is the vet so Tom gets to go in, and Buster responds well to Tom.

Tom keeps coming back, though Charlie insists he pay admission.

At school, there are drills where the kids wear gas masks and get down on the floor. Later, two kids at a time go inside a truck to test the gas masks, and this is done several times during the movie.

Vernon and Pete are bullies who pick on Tom, among others. Jane tells them to stop, but Tom is ridiculed because he needs a girl to fight his battles for him.

Every now and then, the people must go into a shelter because of bombing.

Tom's father gets called to serve in the war. When Tom goes back to the zoo, he is allowed to work with the new vet Jake, at least for a while, and he keeps telling Jake how his father does things. Tom writes to his father but his father never seems to respond.

Vernon and Pete also bully kids in Tom's neighborhood. They tell scary stories about Mrs. Austin, who keeps numerous animals and yells at anyone who comes around. Tom tries to help Mrs. Austin when the bullies get kids to throw stuff at her house, but she isn't very friendly.

One night, Tom sees Pete with his brother Mickey, a little person. Pete pleads with Tom not to tell anyone about his brother because of the way people will treat him.

Because of the bombings, the decision is made to kill the dangerous animals at the zoo, since they could escape if the zoo is hit. It's too late for Gilbert the Lion and other animals, but Tom must save Buster. Tom goes to the hospital where his mother works as a nurse but she doesn't seem to care. People are her priority.

One day while in the woods, Tom meets Jane and they become friends. They end up going to the movies together, where the newsreel shows that Hitler is threatening other countries but at least some of his planes are being shot down. Jane claims her father is fighting in the war but Tom sees her helping a drunk man go inside her house.

Later, Tom recruits Jane to help him break Buster out of the zoo. There is an entrance that is never used where people won't see them. Tom has his father's keys. However, they need someone strong. Pete is willing to help.

When the time comes to actually free Buster, Pete has to bring along Mickey to keep him from waking their mother. Mickey explains that people treat him like a child who can't do anything, but he's just little and can do anything they can do. So he gets to come along. After sneaking in the other entrance the group succeeds in freeing Buster, but as they try to exit, there are two problems. Tom's father's keys are still inside, and Charlie catches the group. However, Charlie lets them have his keys and indicates he will not say anything. But there is a new problem. Mickey is missing.

Mickey gets caught by one of the curfew patrol, but he is able to persuade them to simply take him back home, where the other kids hear him telling the story of what happened. Only it's not a true story, but he is believed.

Buster has been hidden but has to find a permanent residence. Tom managed to become friendly enough with Mrs. Austin to be able to ask her to hide the elephant. She is reluctant but eventually agrees. However, Buster is sick and Tom will have to find a way to get medication.

When Buster is found to be missing, the zoo's management blame Charlie. Charlie quits rather than admit what he did.

There is a reward for the return of Buster. Vernon and Pete are interested, or at least Pete is pretending to go along since he has to hide his knowledge of the situation.

There is a German attack on Belfast, and this one is serious, as buildings are damaged that weren't before. The people go into the shelter, but Tom and Jane leave to go get Buster's medication.

Tom is able to successfully treat Buster, who starts getting better. But at school, the teacher announces Jane died in the bombing before she could get back home. Pete blames Tom for Jane's death. And Tom is very depressed over what happened, though his mother tries to assure him it wasn't his fault.

Later, Tom has to get up and get going and live his life. The more time he spends with Mrs. Austin taking care of Buster, the more she treats him like a son. Both of them feel they now have a purpose in life. Mrs. Austin shows Tom a photo of her son and letters he sent. She explains he died in The Great War.

Vernon sees Buster and tries to report what he saw hoping to claim the reward, but the zoo is locked. However, before he can go to the police, Tom has successfully returned Buster, and the other vet promises not to say anything. Tom wondered why Jake wouldn't serve in the war, but he sees Jake when he has trouble breathing and has to take a drink. This explains it. Vernon arrives at the police station but the cops get the news that Buster is back, and Vernon is ignored.

Tom finds the letters he sent his father, which his mother never sent. He understands.

Later, Tom and Mrs. Austin, now in a wheelchair, visit Buster at the zoo. Charlie, back at work, of course charges admission. Tom's father joins them.

Tom as an adult narrates the ending of the movie. He says Mrs. Austin lived about twenty more years. He says Pete became a doctor specializing in children with developmental problems. And Tom continues to visit Jane's grave.