To help you understand the play more clearly, here is a list of the characters:
In the story read by his teacher Siobhan, 15-year-old Christopher finds his neighbour’s dog Wellington dead, with a garden fork sticking out of its body. After being mistakenly accused of the act by his neighbour Mrs Shears, he becomes distressed and collapses to the ground.
A police officer asks Christopher if he killed the dog, which he denies. However, when the police officer tries to lift him, Christopher – still distressed – hits him, and is arrested.
The scene shifts back and forth between Siobhan reading from Christopher’s book and his conversation with a sergeant at the police station.
We learn that Christopher finds “people confusing”. He also has difficulties picking up on social cues and expressions. As a result, he struggles to communicate clearly with the sergeant. This frustrates the sergeant, who eventually gives Christopher a warning. Afterwards, his father Ed takes him home.
Back at home, Christopher informs his father that he intends to investigate Wellington’s murder. However, Ed advises him against it, urging him to keep his “nose out of other people’s business.”
At school, Siobhan shares a passage from the book where Christopher learns of his mother’s death from a heart attack. Rather than showing emotion, he responded with a logical question about the specifics of her heart condition.
Christopher begins documenting the events surrounding Wellington’s death. He later tells Mrs Shears that he wasn’t responsible for the dog’s death and plans to investigate the matter, but she is not interested in discussing it with him.
Christopher talks to his neighbours to gather information about Wellington’s death. Mrs Alexander offers him snacks, but when she steps away to get them, he fears she might call the police and decides to leave.
He concludes that the dog was killed to upset Mrs Shears. This leads him to suspect Mr Shears, her former husband, as the prime suspect.
Ed insists that the school let Christopher take his A-level maths this year, even though he is younger than the usual age.
At home, Christopher passionately talks about his ambition to become an astronaut, a topic that frustrates his father. When the conversation shifts to Christopher’s investigation into Wellington’s death and his identification of a main suspect, Ed becomes extremely angry at the mention of Mr Shears’s name. He demands that Christopher stop his investigation immediately.
Later at school, Christopher informs Siobhan that he has to abandon his investigation.
In their neighbourhood, Christopher talks with Mrs Alexander. Without discussing Wellington’s death directly, he asks about Mr Shears and mentions that his mother has passed away, leaving Mrs Alexander stunned. She brings Christopher to the park and discloses that his mother had an affair with Mr Shears.
Later at school, Christopher shares this news with Siobhan, displaying no emotional response. He believes that since his mother is dead, the revelation doesn’t affect him. He then recalls a past visit to the beach with his mother, during which she fantasised about living a different life in France with a different partner.
Ed finds Christopher’s book and realises that Christopher has been asking about Mr Shears. This angers Ed, leading to a confrontation with Christopher before he takes the book away.
Later, while alone at home, Christopher hunts for his book and eventually finds it hidden in his father’s wardrobe. In the same place, he stumbles upon numerous letters from his mother, dated after her supposed death. Learning she is alive and reading her accounts of struggling at home overwhelms him, making him vomit.
Upon returning and noticing that Christopher has found the letters, Ed tries to explain why he lied about her death. He claims that couldn’t find a way to truthfully explain the circumstances at the time. Ed also admits to killing Wellington during a fit of rage following a heated dispute with Mrs Shears, with whom he had a romantic relationship.
Ed reassures Christopher of his trustworthiness, but Christopher, now fearful for his safety and suspecting that his father might harm him as he did Wellington, decides to flee and locate his mother in London.