Harrison is an eleven-year-old immigrant from Ghana adapting to life in a London estate. He brings a literal-minded innocence and deep religious faith to his gritty new surroundings. Along with his friend Dean, he attempts to solve a local murder using television detective techniques.

Lydia is Harri's older sister who immigrated to England alongside him and their mother. She manages the social expectations of teenage life in the estate, balancing a desire for popularity with her underlying family loyalty. She frequently adopts a tough exterior to mask her ongoing struggle to adapt to her new environment.

X-Fire is the ringleader of the Dell Farm Crew, a local youth gang that dominates the schoolyard and neighborhood through intimidation. He attempts to recruit younger boys into his ranks by giving them criminal missions to complete, treating failure as an act of defiance.

Killa is an aggressive member of the Dell Farm Crew who uses violence to secure his position in the neighborhood hierarchy. He is quick to threaten others and demands absolute obedience from those around him, especially his girlfriend.

A bird that visits Harri's balcony at the estate. The pigeon provides a serious, adult-like perspective on the events unfolding in the neighborhood, observing the human world much like it watches the food chain. It serves as Harri's primary confidant during his adjustment to London.

Dean is Harri's loyal friend and primary partner in their neighborhood investigation. He brings his knowledge of television detective shows to their crime-solving efforts, explaining concepts like DNA and fingerprinting. He sticks close to Harri while managing the volatile schoolyard dynamics.

Mamma Opoku is Harri and Lydia's hardworking mother who works night shifts at a local hospital delivering babies. She maintains a conservative, religious household and actively tries to shield her children from the harsh realities of their London estate.

Auntie Sonia is Harri's aunt who lives in the same London area. Unlike her sister, she believes the children should be exposed to the difficult truths of their environment. She dates a dangerous man and resorts to extreme measures, like burning her own fingerprints, to cope with her compromised situation.

Julius is a powerful man who sells black-market visas and exerts control over the local immigrant community. He carries a bat called the "Persuader" and maintains a tight grip on Auntie Sonia's life while engaging in fraudulent business activities.

Miquita is a bossy teenager closely associated with the Dell Farm Crew through her relationship with Killa. She spends time at the Opoku apartment with Lydia, using intimidation and physical harassment to assert dominance over both Lydia and Harri.

Poppy is a young girl at Harri's school who returns his youthful affection. She represents a bright spot in Harri's stressful daily life, engaging in innocent schoolyard romance and passing notes in class.

Mr. Frimpong is an elderly member of The Jubilee Center church community known for his loud singing voice. He represents a deep, unwavering devotion to God and serves as a spiritual anchor for Harri in England.

Agnes is Harri's baby sister who temporarily remains in Ghana with their father. Harri thinks of her frequently, holding onto memories of her laughter as a vital connection to his family's roots and his past life.

Papa is Harri's father, who stays behind in Ghana while the rest of the family moves to London. He remains a strong guiding presence in Harri's mind, having taught him valuable lessons about hard work and responsibility.

Altaf is a Somalian boy who lives in Harri's apartment tower. He shares a love of superheroes and drawing with Harri, bonding over their shared experiences as young immigrants.

Connor is a classmate of Harri and Dean who enjoys playing word tricks on his peers. He is known around the schoolyard for telling tall tales and spreading rumors about the neighborhood.

Terri is a local boy who owns a dog named Asbo. He participates in Harri and Dean's attempts to use the dog for detective work, helping test the animal against members of the local gang.

Asbo is Terri Takeaway's dog. The boys attempt to train the animal to locate evil individuals to assist in their ongoing investigation into the neighborhood murder.