RTE2 are loving the Louis Theroux documentaries at the moment and have another one in store for us tonight. Louis travels to San Francisco where pioneering medical professionals are helping children who say they were born in the wrong body to transition from one sex to the other. He meets youngsters who have diagnosed with gender dysphoria and who are undergoing medical interventions, from puberty blockers to hormone-replacement therapy and ultimately gender-reassignment surgery. Louis spends time with the clinic's patients and their families as they negotiate their way along this life-changing and emotional journey.