revor Strathmore was hunched at his desk when Susan arrived breathless at his door. His head was down, his sweaty head glistening in the light of his monitor. The horns on the sublevels blared.

Susan raced over to his desk. "Commander?"

Strathmore didn't move.

"Commander! We've got to shut down TRANSLTR! We've got a—"

"He got us," Strathmore said without looking up."Tankado fooled us all…"

She could tell by the tone of his voice he understood. All of Tankado's hype about the unbreakable algorithm…auctioning off the pass-key—it was all an act, a charade. Tankado had tricked the NSA into snooping his mail, tricked the minto believing he had a partner, and tricked them into downloading a very dangerous file.

"The mutation strings—" Strathmore faltered.

"I know."

The commander looked up slowly. "The file I downloaded off the Internet … it was a…"

Susan tried to stay calm. All the pieces in the game had shifted. There had never been any unbreakable algorithm—never any Digital Fortress. The file Tankado had posted on the Internet was an encrypted virus, probably sealed with some generic, mass-market encryption algorithm, strong enough to keep everyone out of harm's way—everyone except the NSA. TRANSLTR had cracked the protective seal and released the virus.

"The mutation strings," the commander croaked." Tankado said they were just part of the algorithm. "Strathmore collapsed back onto his desk.

Susan understood the commander's pain. He had been completely taken in. Tankado had never intended to let any computer company buy his algorithm. There was no algorithm. The whole thing was a charade. Digital Fortress was a ghost, a farce, a piece of bait created to tempt the NSA. Every move Strathmore had made, Tankado had been behind the scenes, pulling the strings.

"I bypassed Gauntlet." The commander groaned.

"You didn't know."

Strathmore pounded his fist on his desk. "I should have known! His screen name, for Christ's sake! NDAKOTA! Look at it!"

"What do you mean?"

"He's laughing at us! It's a goddamn anagram!"

Susan puzzled a moment. NDAKOTA is an anagram? Shepictured the letters and began reshuffling them in her mind. Ndakota… Kado-tan… Oktadan… Tandoka… Her knees went weak. Strathmore was right. It was as plain as day. How could they have missed it? North Dakota wasn't a reference to the U.S. state at all—it was Tankado rubbing salt in the wound! He'd even sent the NSA a warning, a blatant clue that he himself was NDAKOTA. The letters spelled TANKADO. But the best code-breakers in the world had missed it, just as he had planned.

"Tankado was mocking us," Strathmore said.

"You've got to abort TRANSLTR," Susan declared.

Strathmore stared blankly at the wall.

"Commander. Shut it down! God only knows what's going on in there!"

"I tried," Strathmore whispered, sounding as faint as she'd ever heard him.

"What do you mean you tried?"

Strathmore rotated his screen toward her. His monitor had dimmed to a strange shade of maroon. At the bottom, the dialogue box showed numerous attempts to shut down TRANSLTR. They were all followed by the same response:

SORRY. UNABLE TO ABORT.

SORRY. UNABLE TO ABORT.

SORRY. UNABLE TO ABORT.

Susan felt a chill. Unable to abort? But why? She feared she already knew the answer. So this is Tankado's revenge? Destroying TRANSLTR! For years Ensei Tankado had wanted the world to know about TRANSLTR, but no one had believed him. So he'd decided to destroy the great beast himself. He'd fought to the death for what he believed—the individual's right to privacy.

Downstairs the sirens blared.

"We've got to kill all power," Susan demanded. "Now!"

Susan knew that if they hurried, they could save the great parallel processing machine. Every computer in the world—from Radio Shack PCs to NASA's satellite control systems—had abuilt-in fail-safe for situations like this. It wasn't a glamorous fix, but it always worked. It was known as "pulling the plug."

By shutting off the remaining power in Crypto, they could force TRANSLTR to shut down. They could remove the virus later. It would be a simple matter of reformatting TRANSLTR's hard drives. Reformatting would completely erase the computer's memory—data, programming, virus, everything. In most cases, reformatting resulted in the loss of thousands of files, sometimes years of work. But TRANSLTR was different—it could be reformatted with virtually no loss at all. Parallel processing machines were designed to think, not to remember. Nothing was actually stored inside TRANSLTR. Once it broke a code, it sent the results to the NSA's main databank in order to—

Susan froze. In a stark instant of realization, she brought her hand to her mouth and muffled a scream. "The main databank!"

Strathmore stared into the darkness, his voice disembodied. He'd apparently already made this realization. "Yes, Susan. The main databank. …"

Susan nodded blankly. Tankado used TRANSLTR to put a virus in our main databank.

Strathmore motioned sickly to his monitor. Susan returned her gaze to the screen in front of her and looked beneath the dialogue box. Across the bottom of the screen were the words:

TELL THE WORLD ABOUT TRANSLTR

ONLY THE TRUTH WILL SAVE YOU NOW…

Susan felt cold. The nation's most classified information was stored at the NSA: military communication protocols, SIGINT confirmation codes, identities of foreign spies, blueprints for advanced weaponry, digitized documents, trade agreements—the list was unending.

"Tankado wouldn't dare!" she declared. "Corrupting a country's classified records?" Susan couldn't believe even Ensei Tankado would dare attack the NSA databank. She stared at his message.

ONLY THE TRUTH WILL SAVE YOU NOW

"The truth?" she asked. "The truth aboutwhat?"

Strathmore was breathing heavily. "TRANSLTR," hecroaked. "The truth about TRANSLTR."

Susan nodded. It made perfect sense. Tankado was forcing the NSA to tell the world about TRANSLTR. It was blackmail after all. He was giving the NSA a choice—either tell the world about RANSLTR or lose your databank. She stared in awe at the text before her. At the bottom of the screen, a single line was blinked menacingly.

ENTER PASS-KEY

Staring at the pulsating words, Susan understood—the virus, the pass-key, Tankado's ring, the ingenious blackmail plot. The pass-key had nothing to do with unlocking an algorithm; it was an antidote. The pass-key stopped the virus. Susan had read a lot about viruses like this—deadly programs that included abuilt-in cure, a secret key that could be used to deactivate them. Tankado never planned to destroy the NSA databank—he just wanted us go public with TRANSLTR! Then he would give us the pass-key, so we could stop the virus!

It was now clear to Susan that Tankado's plan had gone terribly wrong. He had not planned on dying. He'd planned on sitting in a Spanish bar and listening to the CNN press conference about America's top-secret code-breaking computer. Then he'd planned on calling Strathmore, reading the pass-key off the ring, and saving the databank in the nick of time. After a good laugh, he'd disappear into oblivion, an EFF hero.

Susan pounded her fist on the desk. "We need that ring!I t's the only pass-key!" She now understood—there was no North Dakota, no secondpass-key. Even if the NSA went public with TRANSLTR, Tankado was no longer around to save the day.

Strathmore was silent.

The situation was more serious than Susan had ever imagined. The most shocking thing of all was that Tankado had allowed it to go this far. He had obviously known what would happen if the NSA didn't get the ring—and yet, in his final seconds of life, he'd given the ring away. He had deliberately tried tokeep it from them. Then again, Susan realized, what could she expect Tankado to do—save the ring for them, when he thought the NSA had killed him?

Still, Susan couldn't believe that Tankado would have allowed this to happen. He was a pacifist. He didn't want to wreak destruction; all he wanted was to set the record straight. This was about TRANSLTR. This was about everyone's right to keep a secret. This was about letting the world know that the NSA was listening. Deleting the NSA's databank was an act of aggression Susan could not imagine Ensei Tankado committing.

The sirens pulled her back to reality. Susan eyed the debilitated commander and knew what he was thinking. Not only were his plans for a back door in Digital Fortress shot, but his carelessness had put the NSA on the brink of what could turn out to be the worst security disaster in U.S. history.

"Commander, this is not your fault!" she insisted over the blare of the horns. "If Tankado hadn't died, we'd have bargaining power—we'd have options!"

But Commander Strathmore heard nothing. His life was over. He'd spent thirty years serving his country. This was supposed to be his moment of glory, his pièce de résistance—a back door in the world encryption standard. But instead, he had sent a virus into the main databank of the National Security Agency. There was no way to stop it—not without killing power and erasing every last one of the billions of bytes of irretrievable data. Only the ring could save them, and if David hadn't found the ring by now…

"I need to shut down TRANSLTR!" Susan took control."I'm going down to the sublevels to throw the circuitbreaker."

Strathmore turned slowly to face her. He was a broken man."I'll do it," he croaked. He stood up, stumbling ashe tried to slide out from behind his desk.

Susan sat him back down. "No," she barked. "I'm going." Her tone left no room fordebate.

Strathmore put his face in his hands. "Okay. Bottom floor.Beside the freon pumps."

Susan spun and headed for the door. Halfway there, she turnedand looked back. "Commander," she yelled. "This isnot over. We're not beaten yet. If David finds the ringin time, we can save the databank!"

Strathmore said nothing.

"Call the databank!" Susan ordered. "Warn themabout the virus! You're the deputy director of the NSA.You're a survivor!"

In slow motion, Strathmore looked up. Like a man making thedecision of a lifetime, he gave her a tragic nod.

Determined, Susan tore into the darkness.