The wave of scandals that would engulf Spain began with a police raid on a wooded property outside Madrid. It was Nov. 3, 2017, and the target was José Manuel Villarejo Pérez, a former government spy. Villarejo’s name had been circulating in the Spanish press for years. He was rumored to have had powerful friends and to have kept dirt on them all. The impressive variety of allegations against him — forgery, bribery, extortion, influence peddling — had earned him the nickname “king of the sewers.”

For many decades, Villarejo’s face had been known to almost no one. He was, after all, a spy — and not just any spy, but one who had started his career in the secret police of the Spanish dictator Francisco Franco. In those years, he would dress in overalls from Telefónica, the national telephone company, as he conducted surveillance operations in the mountains, and on several occasions he even wore a priest’s collar in order to infiltrate the Basque separatist group ETA. More recently, Villarejo had taken to simply introducing himself as a lawyer who ran a private-investigation firm, offering those he met to dig up compromising material on their enemies. His formal connection to the government was increasingly ambiguous. Of all of the identities he assumed over the years, this was perhaps the most powerful one. It made him rich through the hefty fees he charged, and it opened a door into the worlds of business tycoons, government ministers, aristocrats, judges, newspaper editors and arms traffickers — all of whose trust he gained, all of whose private words he taped.

Villarejo was handcuffed and taken to Madrid. But as he sat in jail awaiting trial, the question left hanging over Spain was this: What happens to a country’s secrets when they have all been recorded by one man? And what happens when that man finds himself suddenly backed into a corner?

This story was recorded by Audm. To hear more audio stories from publications like The New York Times, download Audm for iPhone or Android.

Unlock full access to New York Times podcasts and explore everything from politics to pop culture. Subscribe today at nytimes.com/podcasts or on Apple Podcasts and Spotify.