The story explores the divisive debate over whether a child should be free to make permanent changes to their gender. Dr Kenneth Zucker once ran the largest public clinic in Toronto for treating children and adolescents with gender dysphoria: an often violent feeling that the body they were born in does not match their true gender. But then he was fired and his clinic closed down amid comparisons to a religious zealot trying to 'cure' homosexuality. His supporters believe he is a victim of a virulent form of transgender politics that stifles freedom of speech. It features interviews with Zucker, his patients, the families, the clinicians and transgender activists.

• Ade Adepitan
• Carrie Gracie
• Simon Reeve