Lewis traces the moment his once deeply held Covid-19 conspiracy theories began to unravel. It was in September last year, when a doctor engaged him and fellow activists in conversation as they handed out leaflets in a Liverpool park. “We were always open to debate and she wasn’t hostile to us either. She just wanted to prove us wrong. One of the things she did was to point me to an article in the Lancet about the number of deaths,” he said, referring to the peer-reviewed general medical journal. “From then on I was looking at the data, which I...