Michel Thierry Atangana Abega spent 17 years in detention in Cameroon, locked in a tiny underground cell. He was alone for nearly all that time, denied access to lawyers and doctors and dependent on charity to supplement meager, state-issued rations. His primary connection to the outside world came from a radio that carried local stations and, sometimes, Radio France Internationale and the BBC.

Born in Cameroon in 1964, Atangana studied in France and became a naturalized French citizen in 1988. He embarked on a career as a financial engineer and, in 1994, traveled back to Cameroon to develop road projects. It was in that capacity, he says, that he got to know Titus Edzoa, who was then a high-ranking official in the president’s office in Yaounde. ...