It is 35 years since Sr Helen Prejean first watched a man being executed, but the fire it ignited in her soul still burns brightly. That’s her own description of the event: she quotes me the opening paragraph of her memoir, which will be published later this year.

“They killed a man with fire one night,” she recites. “They strapped him to a wooden chair and pumped electricity through his body until he was dead. His killing was a legal act, because he had killed. No religious leaders protested the killing that night, but I was there. I saw it with my own eyes; and what I saw set my soul on fire.”