Now, Jason thought that Katrina looked a bit off kilter as she turned to look once again through the window into the robot room. "Anyway," he said, "the data is at my desk. You want it?"

Katrina took a breath. "OK here's the deal. I just had a visit-not a phone call, a visit-from two FBI special agents. They described a strain of anthrax carrying an activator. And they showed me a doc.u.ment threatening a bioterror attack.

"They want to fund our research to stop it. But they don't trust me. At all. At one point in our conversation, they literally pulled their guns on my a.s.s. I think there's a strong possibility that in the near future, there will be feds crawling all over our lab. They have some rudimentary information about the activator strain that they found. I don't think we should share anything about our activator, because I don't know how close in structure it might be."

In his reflection on the sash of the tissue culture hood, Jason could see that he had turned from gray to white. He slumped in his chair, panting. His flu felt worse every second. "Wow," he said weakly. After a lengthy pause, he swallowed and then sighed. "Yeah, I guess you're right. What would they think if they found the data?"

Katrina continued, "I still want to keep the data for the same reasons I did before. But it has to be somewhere they can't find it-even if they turn our lab and our offices completely upside down, which I think they might. I don't want it at my house, nor do I recommend that you take it home. Who knows if they'll raid our residences. So what can we do with it?"

Jason shook his head. "Hold on a minute." He turned off the tissue culture hood and returned his cells to the incubator.

Together, Katrina and Jason walked out into the robot room and began looking around, as if regarding the familiar laboratory for the first time. Other than a few cabinets and the large stations supporting the robot and its incubator, there was not much in the room.

They walked back out into the main lab. Oxana was now gone, and the laboratory was vacant. Jason led Katrina to his desk. He pulled down a jumbled notebook crammed with loose pages of data and flipped through it until he found what he was looking for. He removed the pages of interest and set the notebook down on the desk.

"This is all of it," Jason said. "None of it is really written up for anyone to read other than me, since we never followed up with these compounds. And I never bothered entering it into the computer database. I can delete the one raw file from Octopus that identified the compound."

They wandered back out into the lab and continued looking around. Katrina looked up at the ceiling. "You think we could put it in a light fixture?" But then she added, "Oh, duh. It would cut off the light. Nevermind."

Jason began to consider the option of destroying the data entirely. "You sure you want to keep it?"

"Yes," Katrina said emphatically. "We might need it to work on an antidote for the activated strain. We can't destroy it. I'm at a loss."

Jason looked deeply into her face, wanting to know more about the antidote project, wondering what to do with the activator data. And then suddenly, he knew.

He could not contain the grin that now spread over his face. He turned without a word and began walking.

Curious, Katrina followed.

Jason walked briskly back through the robot room into the cell culture room. He turned and grinned at Katrina, dramatically batted his eyelashes, and then cast his gaze across the room.

In the corner opposite the door stood a large, silver tank connected to two steel reservoirs that fed a constant supply of liquid nitrogen. A digital gauge monitored the dangerously cold element, keeping the temperature at negative 196 degrees Celsius. The tank was equipped with a monitored alarm system that would notify university security if the cooling system failed.

Inside the tank were the most precious items in the lab-all of the mammalian cells and viruses that had been generated since the lab had first been initiated. Years of Katrina's research. And Jason's. The tank's contents would be destroyed if thawed. So the tank could never be emptied without relocating everything inside to another cryogenic location, a task that presented a logistical nightmare.

The FBI would never have reason to look inside the liquid nitrogen, and even if they did, the scientists had a strong argument to stall the effort.

A stepstool alongside the cryogenic tank granted access to the heavy hinged lid, that, when open, almost reached the ceiling. A padlock with a four-numbered code secured the lid.

Jason's eyes moved back to Katrina.

Finally understanding, she giggled. Wordlessly, she began opening drawers and cabinets in the storage island by the door of the room, rifling through the contents as she went.

Jason, who knew the whereabouts of materials in the room better than his boss did, crossed directly to the correct drawer and pulled out a medium sized cryogenic bag. He pulled it open and dropped in the several pages of data. Then he turned and sealed the bag with the heat-sealer that sat next to the microscope.

After mounting the stepstool to reach the padlock, he clamped the heavy plastic bag between his teeth and then rotated the numbers on the lock to the correct sequence. He popped the padlock open.

When Jason swung the heavy door upward, a white cloud of sublimation billowed from the tank. He waved his hand to disperse the upper layers of the thick fog in order to see the towers of cryogenic vials that rested beneath it.

Katrina reached toward a nearby shelf and grabbed a pair of thick, blue, cold-resistant gloves. She handed them up to Jason, and he pulled them on. He then pulled out one of the cryogenic towers, dripping smoking liquid nitrogen onto the cracked linoleum floor.

After pulling out three more towers and setting them beside the first, Jason dropped the bag containing the activator data into the liquid nitrogen tank and watched as it disappeared beneath the murky surface of the vapor.

Jason replaced the metal towers filled with boxes of cryogenic vials, swung the lid back into place, and replaced the padlock. He removed the gloves and turned back to Katrina.

"Well, I guess that about does it," she said.

Jason furrowed his brow. "Now that we've done that, exactly how are we ever going to get the stuff out again?"

Katrina thought for a moment and then smiled. "My daughter volunteers at the humane society," she said. "I have an idea."

4:21 P.M. PDT.

Katrina chose a corner table at the bar. She, Oxana, and Todd were quickly joined by Josh Attle, who had shown up at the lab as she was on her way out. The four of them sat sipping frosty pints of beer and sharing a platter of appetizers while Katrina spoke.

Changing the subject abruptly every time a waitress approached, she first told them in broken sections about her encounter with the FBI. She described the activated anthrax strain and said that they had been asked to work on an antidote. She did not mention the activator that Jason had found.

She then began telling the three students about the threatening card that had been sent to the White House.

Josh interrupted her with, "ISIL sent a greeting card? Is their Twitter account suspended?"

The four scientists laughed, a welcome break from the tension, and then spent a few moments reflecting on the particulars of the card. Katrina only had a vague recollection of its text, which she had quickly skimmed while being held at gunpoint by two federal agents. She wondered if she could obtain a copy, but she antic.i.p.ated that this aspect of the investigation would be deemed 'none of her beeswax' by the feds.

"Listen, you guys," Katrina warned. "If we elect to take on this work, the FBI will become a continuous presence in our lab. I'm sure that probably means media exposure and G.o.d knows what else. Will the exposure be good for us as a lab? h.e.l.l, yeah! But it will also mean total invasion of our privacy-and no room for error.

"These guys are high-strung about this. One second they were shaking my hand. The next, I was looking into the barrels of both of their guns, and I swear I almost peed myself."

The comment drew another laugh from her students.

"I think the tall cute one likes me a bit," Katrina said with a mischievous smile. "But the short one-I think his name is Gilman-obviously had a beef with me right off the bat. He's going to be a thorn in my side."

She then turned to the reason she had invited them to the bar. "If we are going to do this, we need to go big or go home. I want it to be a unanimous decision. I want all of you working on the project. You know it better than anyone, and I trust you all. Truth be told, Jason and Josh are both so independent at this point that they're much more in tune with their own work than I am."

Josh smiled. "Well, you keep up well enough, but I'm glad you don't try to micromanage me after four years."

Katrina smiled back at him and kept talking. "Todd, Oxana, since you still have at least a couple of years left in grad school, I a.s.sume you weren't planning on leaving my lab anytime soon. Same thing goes for Li. However, the dynamics of your projects will change a little bit.

"Todd, we had decided you would take your qualifying exam this spring. That could still be a go, but I would suggest that we change your research proposal to incorporate work on the activated strain in the rest of your doctoral project."

"Do you think I'll still have enough time to prepare for the exam?" Todd asked.

"I think so, but you'll have to go b.a.l.l.s-to-the-wall."

"How long did you prepare for yours?" Todd asked his advisor, and it was immediately obvious he had asked the wrong question.

Josh looked wide-eyed toward Katrina and then looked down.

Katrina said nothing at first. She blinked twice and then swallowed before saying, "Well, mine was a little unusual, Todd... "

The qualifying exam represents a commencement in the career of a budding scientist; it is the test that, once pa.s.sed, authorizes the researcher to embark upon his or her first independent project. For Katrina Stone, the exam marked the absolute decimation of the life she had known.

The week before Katrina's exam was scheduled, she sat at a crowded kitchen table, boring through a mountain of research papers. Beside the papers were an aging laptop computer and a thick molecular biology textbook. Another textbook, ent.i.tled Infectious Diseases, lay opened to a chapter on anthrax.

In the adjacent kitchen, an empty Hamburger Helper box and a frozen vegetable packet were on the counter, and the sink was piled with dishes from several consecutive days. Tom's share of the Hamburger Helper was congealing in the skillet on the stove.

The phone rang, startling the twenty-six-year-old woman out of her concentration. She dropped the pile of papers onto the table and leapt from her chair. Crossing the living room to retrieve the phone, she danced over a minefield of stuffed animals and the hard plastic toys that Tom angrily referred to as "ankle-breakers." As she pa.s.sed the coffee table, she grabbed the remote control and switched off the TV, which had been loudly projecting without an audience for the past two hours. She glanced at the clock. It was 9:35 p.m.

"h.e.l.lo," Katrina said irritably as she picked up the receiver.

"Hey, babe," Tom said casually on the other end.

"Tom, where are you!" It was not a question, but a demand. "You missed dinner again."

"I know-I'm sorry. My car broke down, and my cell phone battery was dead, so I couldn't call until now."

Katrina rolled her eyes and flipped through a stack of bills on the table next to the phone. Several of them were marked in red as overdue. "You sound pretty cheerful for someone stranded at nine thirty on a weeknight."

"I had to get my car to the mechanic, and the tow truck driver took forever. By the time I got here, they were closed, so I had to figure out where I could leave the car overnight.

"It's funny what happened though. I borrowed this jarhead's cell phone. He was just walking by and I could tell he was in the Corps. I showed him my Navy and medical tattoos and asked if I could use his phone. He goes, 'Anytime, Doc.' Anyway, I'm waiting for a taxi now so I'll be home pretty quick."

Katrina glanced away from the stack of unpaid bills and looked at the caller ID. Her stomach knotted. She clicked back to the number from an earlier call, and her knees suddenly felt weak.

Katrina lowered the receiver of the phone to take a deep breath and let it out. Then she returned the receiver to say, "Well, your jarhead friend must have really meant that you could use his phone any time. That same number called our house this morning at ten o'clock."

Silence.

"How do you think that happened, Tom?"

"Look! I don't want to hear your paranoid bulls.h.i.t right now, Katrina! I'm stuck here with no car-"

"Save it! You know, the least you could do is come up with an excuse that makes a little bit of sense when you call me from your girlfriend's f.u.c.king phone. I don't have time for this, Tom. I have a qualifying exam to take next week, and I'm a little busy trying to prepare for it while raising two children. Excuse me, three. So... just enjoy your affair, Doc."

Katrina slammed the phone down and stood panting beside it for several moments. Then she blinked back the tears that were threatening and bit her lip to maintain her composure as she walked down the hall to check on the children. She peeked into Alexis' room first.

The seven-year-old was on the floor in her lavender Care Bear nightgown, happily playing with her ponies. She was quietly talking both to them and for them, altering her tiny voice to create different characters. Her waist-length, straight hair was still held back with the pink bow Katrina had tied around it that morning. The ribbon was now disheveled and drooping to one side, and Lexi's hair was tangled from the long day's activities.

Katrina was initially surprised to find her daughter still awake, and then she remembered with a pang of guilt that she had promised to help her into bed at least an hour earlier.

Alexis looked up at her mother in the doorway and smiled sweetly.

Katrina forced herself to smile back. "It's way past your bedtime, honey," she said quietly. "Brush your teeth and get into bed. In a few minutes, I'll come tuck you in."

Katrina crossed the hall to glance into Christopher's room and confirm that her son was asleep. When she opened the door, the five-year-old made a light cooing noise but then settled back down. Katrina watched him for a moment.

Christopher's blonde curls sprang wildly from around his cherubic face, and one chubby fist was resting against a rosy cheek. His blanket had pulled down in his sleep, and his pudgy belly was peeking out from beneath a soft flannel pajama top.

Blinking back tears, Katrina tiptoed toward her only son and pulled the cover over him. Then she crept away and quietly closed the door to his room. She stepped into the hallway bathroom-the only one in their house-and closed the door. She pulled back the auburn hair that fell in thick waves down her back and knotted it quickly into a bun. Then she splashed a few handfuls of cold water on her face and gulped down a few quick breaths of air. The threat of tears gradually subsided. For a long moment, she stared blankly into the mirror, and the blue-gray eyes of the woman staring back reflected sheer exhaustion.

When she felt calm enough to do so, Katrina fulfilled her promise to her daughter. Sitting on the edge of Alexis' bed, she gently pulled the sagging bow from the girl's long hair and brushed it out, beginning at the tips.

"Is Daddy coming home now?" Alexis asked quietly.

"I think so," Katrina said. "He had a problem with his car, but he should be on the way. So go to sleep. I love you."

Alexis lay down obediently and allowed Katrina to pull her covers up over her nightgown to her neck. Katrina kissed her forehead, and Lexi kissed her own tiny fingers and then planted them onto her mother's lips. "I love you more," Alexis said, giggling.

After leaving her daughter's room, Katrina rushed quickly down the hall into the master bedroom, where she locked the door behind her. She finally let herself break down, and she sat down on the bed weeping as quietly as she could.

Then there was a crash and a breaking of gla.s.s. She ran into the living room and screamed.

4:43 P.M. PDT.

Her work history was as impressive as Guofu Wong had said, and it showed in her Homeland Security file. What surprised Sean McMullan was the financial status of the allegedly brilliant young doctor. Katrina Stone was broke and had been for her entire life.

McMullan had no idea that Ph.D.-level researchers made so little after going to school for so long. Stone had twenty years of education-and education expenses-under her belt. And she made less money than a successful plumber. G.o.d, what a rip-off, McMullan thought.

As he skimmed through the financial record, he found a myriad of odd jobs that she had worked, from bartending while in graduate school back to topless dancing in college. The latter was only a six-month employment, and he noticed it ended when she got married. The FBI agent tried to envision the cla.s.sy, professional woman he had met earlier that afternoon shaking it in a t.i.ttie bar, but couldn't.

Then he saw the legal section of the file, and a queer idea began to form in his mind.

McMullan began reviewing his notes from the prison.

At present, San Quentin is home to more than four hundred death row inmates. The majority of dead men walking live in East Block-the largest of three death row areas. While some basic freedoms are granted in East Block, a violation of the rules will land the offender in The Adjustment Center, where the inmate's phone calls, visitation, and other luxuries are stripped from him.

The original death row wing of the prison-North Seg-is now the coveted wing among death row inmates. Those who exhibit stellar behavior must actively pet.i.tion to reside in North Seg, and once there, the slightest infraction will send them back to East Block.

The anthrax outbreak at San Quentin had been confined exclusively to North Seg-the country club among death row inmates and home of the most well-mannered rapists, murderers, and child molesters in California.

No other area of the prison had been touched.

Sean McMullan had been expecting the legal section of Katrina Stone's file to be mostly blank. Instead, he found several hundred pages of doc.u.mentation detailing several years of legal struggle.