Strathmore cut her off. "Susan, it's crystal clear.Tankado engraved the Digital Fortress pa.s.s-key on his ring. Gold isdurable. Whether he's sleeping, showering, eating-thepa.s.s-key would always be with him, ready at a moment's noticefor instant publication."

Susan looked dubious. "On his finger? In the open likethat?"

"Why not? Spain isn't exactly the encryption capitalof the world. n.o.body would have any idea what the letters meant.Besides, if the key is a standard sixty-four-bit-even in broaddaylight, n.o.body could possibly read and memorize all sixty-fourcharacters."

Susan looked perplexed. "And Tankado gave this ring to atotal stranger moments before he died? Why?"

Strathmore's gaze narrowed. "Why do youthink?"

It took Susan only a moment before it clicked. Her eyeswidened.

Strathmore nodded. "Tankado was trying to get rid of it. Hethought we'd killed him.

He felt himself dying and logicallya.s.sumed we were responsible. The timing was too coincidental. Hefigured we'd gotten to him, poison or something, a slow- actingcardiac arrestor. He knew the only way we'd dare kill him isif we'd found North Dakota."

Susan felt a chill. "Of course," she whispered."Tankado thought that we neutralized his insurance policy sowe could remove him too." It was all coming clear to Susan. The timing of the heart attackwas so fortunate for the NSA that Tankado had a.s.sumed the NSA wasresponsible. His final instinct was revenge. Ensei gave away hisring as a last-ditch effort to publish the pa.s.s-key.

Now,incredibly, some unsuspecting Canadian tourist held the key to themost powerful encryption algorithm in history.

Susan sucked in a deep breath and asked the inevitable question."So where is the Canadian now?"

Strathmore frowned. "That's the problem."

"The officer doesn't know where he is?"

"No. The Canadian's story was so absurd that theofficer figured he was either in shock or senile. So he put the oldguy on the back of his motorcycle to take him back to his hotel.But the Canadian didn't know enough to hang on; he fell offbefore they'd gone three feet-cracked his head and brokehis wrist."

"What!" Susan choked.

"The officer wanted to take him to a hospital, but theCanadian was furious-said he'd walk back to Canada beforehe'd get on the motorcycle again. So all the officer could dowas walk him to a small public clinic near the park. He left himthere to get checked out."

Susan frowned. "I a.s.sume there's no need to ask whereDavid is headed."

CHAPTER 17

David Becker stepped out onto the scorching tile concourse ofPlaza de Espana. Before him, El Ayuntamiento-the ancientcity council building-rose from the trees on a three-acre bedof blue and white azulejo tiles. Its Arabic spires and carvedfacade gave the impression it had been intended more as a palacethan a public office. Despite its history of military coups, fires,and public hangings, most tourists visited because the localbrochures plugged it as the English military headquarters in thefilm Lawrence of Arabia. It had been far cheaper forColumbia Pictures to film in Spain than in Egypt, and the Moorishinfluence on Seville's architecture was enough to convincemoviegoers they were looking at Cairo. Becker reset his Seiko for local time: 9:10 p.m.-stillafternoon by local standards; a proper Spaniard never ate dinnerbefore sunset, and the lazy Andalusian sun seldom surrendered theskies before ten.

Even in the early-evening heat, Becker found himself walkingacross the park at a brisk clip. Strathmore's tone had soundeda lot more urgent this time than it had that morning. His neworders left no room for misinterpretation: Find the Canadian, getthe ring. Do whatever is necessary, just get that ring.

Becker wondered what could possibly be so important about a ringwith lettering all over it. Strathmore hadn't offered, andBecker hadn't asked. NSA, he thought. Never SayAnything.

On the other side of Avenida Isabela Catolica, the clinicwas clearly visible-the universal symbol of a red cross in awhite circle painted on the roof. The Guardia officer had droppedthe Canadian off hours ago. Broken wrist, b.u.mped head-no doubtthe patient had been treated and discharged by now. Becker justhoped the clinic had discharge information-a local hotel orphone number where the man could be reached. With a little luck,Becker figured he could find the Canadian, get the ring, and be onhis way home without any more complications.

Strathmore had told Becker, "Use the ten thousand cash tobuy the ring if you have to.

I'll reimburse you."

"That's not necessary," Becker had replied.He'd intended to return the money anyway. He hadn't goneto Spain for money, he'd gone for Susan. Commander TrevorStrathmore was Susan's mentor and guardian. Susan owed him alot; a one-day errand was the least Becker could do.

Unfortunately, things this morning hadn't gone quite asBecker had planned. He'd hoped to call Susan from the planeand explain everything. He considered having the pilot radioStrathmore so he could pa.s.s along a message but was hesitant toinvolve the deputy director in his romantic problems.

Three times Becker had tried to call Susan himself-firstfrom a defunct cellular on board the jet, next from a pay phone atthe airport, then again from the morgue. Susan was not in. Davidwondered where she could be. He'd gotten her answering machinebut had not left a message; what he wanted to say was not a messagefor an answering machine.

As he approached the road, he spotted a phone booth near thepark entrance. He jogged over, s.n.a.t.c.hed up the receiver, and usedhis phone card to place the call. There was a long pause as thenumber connected. Finally it began to ring.

Come on. Be there.

After five rings the call connected. "Hi. This is Susan Fletcher. Sorry I'm not in rightnow, but if you leave your name . .

Becker listened to the message. Where is she? By nowSusan would be panicked. He wondered if maybe she'd gone toStone Manor without him. There was a beep.

"Hi. It's David." He paused, unsure what to say.One of the things he hated about answering machines was that if youstopped to think, they cut you off. "Sorry I didn'tcall," he blurted just in time. He wondered if he should tellher what was going on. He thought better of it. "CallCommander Strathmore. He'll explain everything."Becker's heart was pounding. This is absurd, hethought. "I love you," he added quickly and hung up.

Becker waited for some traffic to pa.s.s on Avenida Borbolla. Hethought about how Susan undoubtedly would have a.s.sumed the worst;it was unlike him not to call when he'd promised to.

Becker stepped out onto the four-lane boulevard. "In andout," he whispered to himself. "In and out." He wastoo preoccupied to see the man in wire-rim gla.s.ses watching fromacross the street.

CHAPTER 18

Standing before the huge plate-gla.s.s window in his Tokyoskyrise, Numataka took a long pull on his cigar and smiled tohimself. He could scarcely believe his good fortune. He had spokento the American again, and if all was going according to thetimetable, Ensei Tankado had been eliminated by now, and his copyof the pa.s.s-key had been confiscated.

It was ironic, Numataka thought, that he himself would end upwith Ensei Tankado's pa.s.s-key. Tokugen Numataka had metTankado once many years ago. The young programmer had come toNumatech Corp. fresh out of college, searching for a job.

Numatakahad denied him. There was no question that Tankado was brilliant,but at the time there were other considerations. Although j.a.pan waschanging, Numataka had been trained in the old school; he lived bythe code of menboko-honor and face.

Imperfection was not to betolerated. If he hired a cripple, he would bring shame on hiscompany. He had disposed of Tankado's resume withouta glance.

Numataka checked his watch again. The American, North Dakota,should have called by now. Numataka felt a tinge of nervousness. Hehoped nothing was wrong. If the pa.s.s-keys were as good as promised, they would unlock themost sought-after product of the computer age-a totallyinvulnerable digital encryption algorithm.

Numataka could embed thealgorithm in tamper-proof, spray-sealed VSLI chips and ma.s.s marketthem to world computer manufacturers, governments, industries, andperhaps, even the darker markets ... the black market of worldterrorists.

Numataka smiled. It appeared, as usual, that he had found favorwith the shichigosan-the seven deities of good luck. NumatechCorp. was about to control the only copy of Digital Fortress thatwould ever exist. Twenty million dollars was a lot ofmoney-but considering the product, it was the steal of thecentury.

CHAPTER 19

"What if someone else is looking for the ring?" Susanasked, suddenly nervous.

"Could David be in danger?"

Strathmore shook his head. "n.o.body else knows the ringexists. That's why I sent David. I wanted to keep it that way.Curious spooks don't usually tail Spanish teachers."

"He's a professor," Susan corrected, immediatelyregretting the clarification. Every now and again Susan got thefeeling David wasn't good enough for the commander, that hethought somehow she could do better than a schoolteacher.

"Commander," she said, moving on, "if you briefedDavid by car phone this morning, someone could have interceptedthe-"

"One-in-a-million shot," Strathmore interrupted, histone rea.s.suring. "Any eavesdropper had to be in the immediatevicinity and know exactly what to listen for."

He put his handon her shoulder. "I would never have sent David if I thought.i.t was dangerous." He smiled. "Trust me. Any sign oftrouble, and I'll send in the pros."

Strathmore's words were punctuated by the sudden sound ofsomeone pounding on the Node 3 gla.s.s. Susan and Strathmoreturned.

Sys-Sec Phil Chartrukian had his face pressed against the paneand was pounding fiercely, straining to see through. Whatever hewas excitedly mouthing was not audible through the soundproofedgla.s.s. He looked like he'd seen a ghost.

"What the h.e.l.l is Chartrukian doing here?" Strathmoregrowled. "He's not on duty today." "Looks like trouble," Susan said. "He probablysaw the Run-Monitor."

"G.o.dd.a.m.n it!" the commander hissed. "Ispecifically called the scheduled Sys-Sec last night and told himnot to come in!"

Susan was not surprised. Canceling a Sys-Sec duty was irregular,but Strathmore undoubtedly had wanted privacy in the dome. The lastthing he needed was some paranoid Sys-Sec blowing the lid offDigital Fortress.

"We better abort TRANSLTR," Susan said. "We canreset the Run-Monitor and tell Phil he was seeing things."

Strathmore appeared to consider it, then shook his head."Not yet. TRANSLTR is fifteen hours into this attack. I wantto run it a full twenty-four-just to be sure."

This made sense to Susan. Digital Fortress was the first everuse of a rotating cleartext function. Maybe Tankado had overlookedsomething; maybe TRANSLTR would break it after twenty-four hours.Somehow Susan doubted it.

"TRANSLTR keeps running," Strathmore resolved. "Ineed to know for sure this algorithm is untouchable."

Chartrukian continued pounding on the pane.

"Here goes nothing." Strathmore groaned. "Back meup."

The commander took a deep breath and then strode to the slidinggla.s.s doors. The pressure plate on the floor activated, and thedoors hissed open.

Chartrukian practically fell into the room. "Commander,sir. I ... I'm sorry to bother you, but the Run-Monitor . .. I ran a virus probe and-"

"Phil, Phil, Phil," the commander gushed pleasantly ashe put a rea.s.suring hand on Chartrukian's shoulder. "Slowdown. What seems to be the problem?"

From the easygoing tone in Strathmore's voice, n.o.body wouldever have guessed his world was falling in around him. He steppedaside and ushered Chartrukian into the sacred walls of Node 3. TheSys-Sec stepped over the threshold hesitantly, like a well- traineddog that knew better.

From the puzzled look on Chartrukian's face, it was obvioushe'd never seen the inside of this place. Whatever had beenthe source of his panic was momentarily forgotten.

He surveyed theplush interior, the line of private terminals, the couches, thebookshelves, the soft lighting. When his gaze fell on the reigningqueen of Crypto, Susan Fletcher, he quickly looked away. Susanintimidated the h.e.l.l out of him. Her mind worked on a differentplane. She was unsettlingly beautiful, and his words always seemedto get jumbled around her. Susan's una.s.suming air made it evenworse.

"What seems to be the problem, Phil?" Strathmore said,opening the refrigerator.

"Drink?" "No, ah-no, thank you, sir." He seemedtongue-tied, not sure he was truly welcome.

"Sir ... I thinkthere's a problem with TRANSLTR."

Strathmore closed the refrigerator and looked at Chartrukiancasually. "You mean the Run-Monitor?"

Chartrukian looked shocked. "You mean you've seen it?"

"Sure. It's running at about sixteen hours, ifI'm not mistaken."

Chartrukian seemed puzzled. "Yes, sir, sixteen hours. b.u.t.that's not all, sir. I ran a virus probe, and it'sturning up some pretty strange stuff."

"Really?" Strathmore seemed unconcerned. "Whatkind of stuff?"

Susan watched, impressed with the commander'sperformance.

Chartrukian stumbled on. "TRANSLTR's processingsomething very advanced. The filters have never seen anything likeit. I'm afraid TRANSLTR may have some sort of virus."

"A virus?" Strathmore chuckled with just a hint ofcondescension. "Phil, I appreciate your concern, I really do.But Ms. Fletcher and I are running a new diagnostic, some veryadvanced stuff. I would have alerted you to it, but I wasn'taware you were on duty today."

The Sys-Sec did his best to cover gracefully. "I switchedwith the new guy. I took his weekend shift."

Strathmore's eyes narrowed. "That's odd. I spoketo him last night. I told him not to come in. He said nothing aboutswitching shifts."

Chartrukian felt a knot rise in his throat. There was a tensesilence.

"Well." Strathmore finally sighed. "Sounds likean unfortunate mix-up." He put a hand on the Sys-Sec'sshoulder and led him toward the door. "The good news is youdon't have to stay. Ms. Fletcher and I will be here all day.We'll hold the fort. You just enjoy your weekend."

Chartrukian was hesitant. "Commander, I really think weshould check the-"

"Phil," Strathmore repeated a little more sternly,"TRANSLTR is fine. If your probe saw something strange,it's because we put it there. Now if you don'tmind ..."

Strathmore trailed off, and the Sys-Secunderstood. His time was up.