My story begins at breakfast in late 2013 in a sunny hotel courtyard in southern Mexico; just me, my double espresso and my laptop. When I flipped the laptop open that morning I was astonished by an email informing me of Pope Francis’ invitation to be the new president of the Pontifical Academy of Social Sciences.

What, I wondered, did a social theorist accustomed to writing academic books and arranging conferences have to offer beyond more books and more meetings? When I returned home, I asked the Pope what he wanted us to investigate. He sent me his reply, handwritten on the back of an envelope: “I think it would be good to examine human trafficking and modern slavery.