When the National Security Agency's invincible code-breaking machine encounters a mysterious code it cannot break, the agency calls in its head cryptographer, Susan Fletcher, a brilliant, beautiful mathematician. What she uncovers sends shock waves through the corridors of power.

Review

"The National Security Agency (NSA) is one setting for this exciting thriller; the other is Seville, where on page 1 the protagonist, lately dismissed from NSA, drops dead of a supposed heart attack. Though dead, he enjoys a dramaturgical afterlife in the form of his computer program. Digital Fortress creates unbreakable codes, which could render useless NSA's code-cracking supercomputer called TRANSLTR, but the deceased programmer slyly embossed a decryption key on a ring he wore. Pursuit of this ring is the engine of the plot. NSA cryptology boss Trevor Strathmore dispatches linguist Dave Becker to recover the ring, while he and Becker's lover, senior code-cracker Susan Fletcher, ponder the vulnerability of TRANSLTR. In Seville, over-the-top chase scenes abound; meanwhile, the critical events unfold at NSA. In a crescendo of murder, infernos, and explosions, it emerges that Strathmore has as agenda that goes beyond breaching Digital Fortress, and Brown's skill at hinting and concealing Strathmore's deceit will rivet cyber-minded readers." Gilbert Taylor Booklist