had been solved. But after a few weeks the headlines disappeared again, obscured by news of a terrorist attack in France, and by the first moves of a presidential race that would end in the election of Donald Trump. Le Roux’s existence receded into the shadows with the most important questions unanswered. Namely, where did he come from, and how had a South African computer programmer managed to create his own global cartel? Why had the government refused to release his identity, and then suddenly leaked it? And where was he now?

I became obsessed with finding out.

As I tried to page back through Le Roux’s history, his story at first seemed borderless, almost limitless. I spent the better part of a year trying to understand him through the same means by which he’d directed his pharmacy business: the Internet. Late at night, after my wife went to bed and then, as time went on, while my newborn daughter slept, I would open my laptop and plunge into a thicket of data. The first hints of Le Roux were faint, puzzling. Here was his name on a Florida company cited in a 2008 Federal Communi- cations Commission complaint about a marketing call made to someone on the National Do Not Call Registry. There was his email address connected to a gun dealer in Manila called Red White & Blue Arms. Here, lodged in a Hong Kong company data- base, was Le Roux establishing Net Trading Ltd. in 2006 before changing its name to Ajax Technology in 2008, then transferring the ownership to someone named Robson Tandanayi. There was Le Roux incorporating another Ajax Technology in the United Kingdom in 2006, with a Dutch address, before again gifting the company to Tandanayi.

Each piece of data seemed to lead to a dozen more, until I began to feel like I was engaged in an elaborate version of the children’s game Concentration. I would find one clue, stash it away, and hope to turn over another that matched it later on. Unbeknownst to me, I was often flipping many of the same cards that Brill and