Istanbul Signal

For readers of John le Carré, Daniel Silva, and Mick Herron.Three weeks before she could switch on the most secure communications network the West had ever built, Dr Elif Şahin — one of the finest cryptographers of her generation — was found face-down in the Bosphorus. Officially, an accident. But Şahin was a swimmer, and in the last six hours of her life she saved sixty-eight pages, four times ov...