ystems security technician Phil Chartrukian had only intendedto be inside Crypto a minute—just long enough to grab somepaperwork he'd forgotten the day before. But it was not tobe.

After making his way across the Crypto floor and stepping intothe Sys-Sec lab, he immediately knew something was not right. Thecomputer terminal that perpetually monitored TRANSLTR'sinternal workings was unmanned and the monitor was switchedoff.

Chartrukian called out, "Hello?"

There was no reply. The lab was spotless—as if no one hadbeen there for hours.

Although Chartrukian was only twenty-three and relatively new tothe Sys-Sec squad, he'd been trained well, and he knew thedrill: There was always a Sys-Sec on duty in Crypto…especially on Saturdays when no cryptographers were around.

He immediately powered up the monitor and turned to the dutyboard on the wall. "Who's on watch?" he demandedaloud, scanning the list of names. According to the schedule, ayoung rookie named Seidenberg was supposed to have started a doubleshift at midnight the night before. Chartrukian glanced around theempty lab and frowned. "So where the hell is he?"

As he watched the monitor power up, Chartrukian wondered ifStrathmore knew the Sys-Sec lab was unmanned. He had noticed on hisway in that the curtains of Strathmore's workstation wereclosed, which meant the boss was in—not at all uncommon for aSaturday; Strathmore, despite requesting his cryptographers takeSaturdays off, seemed to work 365 days a year.

There was one thing Chartrukian knew for certain—ifStrathmore found out the Sys-Sec lab was unmanned, it would costthe absent rookie his job. Chartrukian eyed the phone, wondering ifhe should call the young techie and bail him out; there was anunspoken rule among Sys-Sec that they would watch each other'sbacks. In Crypto, Sys-Secs were second-class citizens, constantlyat odds with the lords of the manor. It was no secret that thecryptographers ruled this multibillion-dollar roost; Sys-Secs weretolerated only because they kept the toys running smoothly.

Chartrukian made his decision. He grabbed the phone. But thereceiver never reached his ear. He stopped short, his eyestransfixed on the monitor now coming into focus before him. As ifin slow motion, he set down the phone and stared in open-mouthedwonder.

In eight months as a Sys-Sec, Phil Chartrukian had never seenTRANSLTR's Run-Monitor post anything other than a double zeroin the hours field. Today was a first.

TIME ELAPSED: 15:17:21

"Fifteen hours and seventeen minutes?" he choked."Impossible!"

He rebooted the screen, praying it hadn't refreshedproperly. But when the monitor came back to life, it looked thesame.

Chartrukian felt a chill. Crypto's Sys-Secs had only oneresponsibility: Keep TRANSLTR "clean"—virusfree.

Chartrukian knew that a fifteen-hour run could only mean onething—infection. An impure file had gotten inside TRANSLTR andwas corrupting the programming. Instantly his training kicked in;it no longer mattered that the Sys-Sec lab had been unmanned or themonitors switched off. He focused on the matter athand—TRANSLTR. He immediately called up a log of all the filesthat had entered TRANSLTR in the last forty-eight hours. He beganscanning the list.

Did an infected file get through? he wondered. Couldthe security filters have missed something?

As a precaution, every file entering TRANSLTR had to passthrough what was known as Gauntlet—a series of powerfulcircuit-level gateways, packet filters, and disinfectant programsthat scanned inbound files for computer viruses and potentiallydangerous subroutines. Files containing programming"unknown" to Gauntlet were immediately rejected. They hadto be checked by hand. Occasionally Gauntlet rejected entirelyharmless files on the basis that they contained programming thefilters had never seen before. In that case, the Sys-Secs did ascrupulous manual inspection, and only then, on confirmation thatthe file was clean, did they bypass Gauntlet's filters andsend the file into TRANSLTR.

Computer viruses were as varied as bacterial viruses. Like theirphysiological counterparts, computer viruses had one goal—toattach themselves to a host system and replicate. In this case, thehost was TRANSLTR.

Chartrukian was amazed the NSA hadn't had problems withviruses before. Gauntlet was a potent sentry, but still, the NSAwas a bottom feeder, sucking in massive amounts of digitalinformation from systems all over the world. Snooping data was alot like having indiscriminate sex—protection or noprotection, sooner or later you caught something.

Chartrukian finished examining the file list before him. He wasnow more puzzled than before. Every file checked out. Gauntlet hadseen nothing out of the ordinary, which meant the file in TRANSLTRwas totally clean.

"So what the hell's taking so long?" he demandedof the empty room. Chartrukian felt himself break a sweat. Hewondered if he should go disturb Strathmore with the news.

"A virus probe," Chartrukian said firmly, trying tocalm himself down. "I should run a virus probe."

Chartrukian knew that a virus probe would be the first thingStrathmore would request anyway. Glancing out at the desertedCrypto floor, Chartrukian made his decision. He loaded the viralprobe software and launched it. The run would take about fifteenminutes.

"Come back clean," he whispered. "Squeaky clean.Tell Daddy it's nothing."

But Chartrukian sensed it was not "nothing."Instinct told him something very unusual was going on inside thegreat decoding beast.