Medicine deals, by necessity, in the reliable knowledge of a science-based discipline. So why did things go so drastically awry for the Tavistock clinic’s Gender Identity Development Service (GIDS). Back in 2005, psychiatrist David Taylor noted a disturbing lack of clarity about the clinic’s goals: was its purpose to treat children with gender dysphoria or did they identify as trans because they were distressed for some other reason? He was concerned too by the “onerous” pressure on staff from trans activist groups, and children themselves, to prescribe “untested and under-researched” puberty blockers.