Editor's note: We are pleased to present the second episode of an original four-part story about an unusual laboratory relationship. (Use the navigation tool above to catch up.)

I am at the sink washing glassware when I hear the snapping of the door handle behind me and turn around. The door opens and a man's head peers in as he leans against the door handle. He is about fifty years old, nearly bald but with a dense mustache and beard. Our graduate student is working at the lab bench by the entrance, and he asks her, in a professional but awkwardly loud voice, if Nancy is in. She says yes, and the man nods and walks into the lab. He wears creased tan slacks without pleats and a navy sweater vest over a light blue shirt.

He throws a diffident greeting toward me, this colleague, barely lifting his eyes and only half raising his left hand in my general direction as he passes on his way toward Nancy's office.

I lower an empty flask into the soapy water and let it go. It floats and jiggles in the plastic tub, clattering between two other pieces of glassware.

I move to the large white incubator outside Nancy's office and open the door. The graduate student watches me suspiciously; I must be discreet. There are no carboys in the incubator, but it is difficult to hear the conversation over the hiss of purified air coming through the metal screen above.

Though I can't make out Nancy's words, her tone is like that of a parent reprimanding a young child. The man answers, but I can't hear him, either. I close the incubator door and begin a slow, leisurely walk past the entrance on my way to the computer desk outside my office.

The man's voice rings with obvious irritation as I pass the entrance. "Just use a note from now on, OK?"

Nancy's voice is still too low for me to hear her response.

I roll the computer chair backward. It accepts my weight with a whisper of a creak.

Nancy leans back in her desk chair, resting her hands on her flat stomach with bemusement. The man stands in front of her desk, leaning forward on both arms. I cannot hear his words from my spot at the computer table, but the agitated bobbing of his head indicates he is quite upset.

As he speaks, Nancy glances toward the entrance. She turns back toward the man, who is still talking, and mutters a couple of words while holding her finger up to signal a pause.

I turn quickly back to the screen, but Nancy has already seen me. She gets up and shuts the door to her office.

The black pen is between my thumb and first finger. I let the tip fall onto the desk. It bounces, then makes a quick, muted drum roll that seems to echo and amplify off the bare walls like my constant breathing. I drop it several more times, studying the rhythm of its bounce, then notice that its point is leaving a black ink mark on the desk, just to the left of one of the fake wood knots.

To the left of the pen sits the piece of paper, tinged yellow by the light filtering through the waxy lampshade. The paper has no lines to guide my handwriting, and so the writing descends at a slight angle from left to right. I have written only three lines so far:

My Dear Angie,

I don't know exactly where to start. I'm so confused myself. How do I begin to explain this to you?

I don't know where to start; that's the problem. Or how to continue, or to end it.

Late back from the lab, I watch silently from behind the door frame. Angie sits at the near end of the table with her back to me while the two children face the wall, the younger nearer to Angie. They are eating green fettuccine noodles tossed with olive oil, garlic, and vegetables. I can smell the cheap grated Parmesan Angie always buys on the thick garlicky air of the kitchen.

Angie's damp hair drops indifferently to her shoulders. With her legs crossed, the parting of the light blue terry robe reveals the thin, pasty skin of her upper thighs. She watches her fork intently as she lifts some fettuccine, then lowers it back down. There is no point to the movement, but she continues all the same.

The children concentrate on their food as well. The hush in the kitchen is almost sacred. The only sound is the buzzing of the fluorescent light overhead, punctuated by the scrapes and clinks of forks and the occasional sucking or light smack of pasta on one of the children's chins.

Leslie, the older, sitting further from Angie, breaks the silence, "Mother . . ."

"What?" she snaps.

"Nothing." The girl lowers her head immediately and begins to twirl her pasta.

"No, what did you want to ask me, sweetie?" Angie pleads in the slow voice she reserves for the children.

With a scowl, Leslie violently plunges her fork straight into the center of her plate and begins to rotate the handle with both hands. Around the fork, the strands of pasta slip easily past one another, all moving in the same spiral at varying rates.

Angie looks down to her lap, sighs and smooths her robe down to mid-thigh.

"Is daddy leaving?" Sammy asks without warning.

Angie looks up. "Where did you get that idea?"

"Leslie said you're losing him just like you lost daddy," he says. His fork is innocently suspended above his right shoulder. A short piece of noodle falls onto his shirt, but he doesn't seem to notice. He's waiting for his answer.

"Leslie, did you say that?" Angie asks.

There follows a long silence. Leslie's fork has assumed a commanding control over the pasta, recruiting strands farther and farther from the center. The strands caress each other, cross each other, slide in and out of loose knots. More than half the plate is now swirling in the massive clockwise spiral.

"Leslie, I'm asking you a question. Did you say that?"

"Mommy, are we going to be alone again?" Sammy persists, oblivious to the rising tension. The fork is still suspended above his shoulder and another noodle falls on his shirt..

"Eat your food before it gets cold," Angie dismisses him. "Leslie, why did you tell him that?"

Leslie bites her bottom lip and stares with conviction at the tiny hands that are controlling the teeming microcosm in front of her. The entire plate has become a whirlpool of green noodle, broccoli, squash and mushroom.

The compressor switches on and begins to hum. On top of the refrigerator, two empty wine bottles begin to tap against each other with a faint clicking sound.

Leslie suddenly pauses, halting the spiral. She surveys the green mound for a moment, then turns to her mother with sadness. "It's true," she says, and shrugs her shoulders.

Angie glares at her daughter.

The scene is gradually blocked behind the door frame as I back away. Best not to confront something like this. The air becomes cooler, cleaner as I leave.

The strong force of the pump drawing liquid through the tubes causes them to jerk spasmodically. My latex-gloved hand holds them steady at the carboy's mouth. I used to let the pump go unattended, but one day the tubing somehow worked itself out and sprayed the concentrated diatom suspension all over the lab. It was not a pretty sight.

I am concentrating the diatom cells, putting them into a smaller volume. This is one of the more tedious procedures in our lab. It lasts over an hour. The pump sucks the diatom-rich seawater from the carboy into a filter stack, where the liquid is drawn out, and returns the concentrated diatoms to the carboy via another hose. The diatoms gradually concentrate into the ever-darkening, ever-descending water in the carboy.

The pump creates such a din. Its motor makes a loud grinding whir like the motor of a heavy truck struggling to climb a steep hill in first gear. The pump's rollers make a wet flapping noise as they run over the tubing, compressing and releasing in rapid-fire succession. The fluid churns and splashes inside the carboy .

Our graduate student works on the other side of the central lab bench. She uses a pair of tweezers to manipulate a small coverslip into a plastic petri dish. Her face is not visible, as the bottles lined along the wooden shelf obscure my view. I can see strands of brownish blond hair resting on the white cotton shoulder of her sweatshirt.

Behind and to her left, Nancy works at the computer desk in front of my office. Her hands punch the keys with a fierce resolve. I have often wondered why Nancy sometimes prefers to work out in the main lab even though she has a computer in her office, but I have never asked her about it.

On the back of her neck, Nancy's dense, rust red hair tapers into a sharp slope of bristly whiskers that curve into a delicate point at her neck's base. She wears olive green pants with two back pockets, one on each side. The edge of a white piece of paper barely reveals itself at the top of the right pocket.

The mirror is covered with water stains, speckled with ancient toothpaste and shaving cream. I brace my hands on the edge of the sink and lean forward. Beneath the grime, I can barely see the image of my own face: wet, aging, spent.

As a hotshot postdoc, I never pictured this moment. I was on top of the world. I was going to have a great future. Nothing could stop me. Now I wonder how long I can keep this up. Now I look through the years and think more about the things I might have done than the ones I have. It's gone so fast, and yet in many ways I seem to have accomplished so little, both personally and professionally. I wish I'd given myself more time to think.

I am working at the fume hood with the glass door opened halfway so that I can stick my arms inside. The air rushes through the opening and up into the massive metal exhaust, creating a low roar.

I am putting fixative into a coverslip chamber. Typically, we spin the diatom cells in a centrifuge down onto thin round glass coverslips. The cells stick to the specially treated coverslips, and then we work with the coverslips – it makes the cells much easier to handle. A V-shaped plastic stand is submerged in a buffered salt solution in a deep glass dish. Narrow grooves hold the coverslips vertical.

Nancy appears to my right as I draw some fixative into the barrel of a syringe. She places a low, wide cardboard tray onto the paper lining beside me. The tray holds about twenty stout, clear glass scintillation vials, all empty and capped with a white plastic lid. She's doing swipes, testing the lab for radioactive contamination. The graduate student in our lab is the only one who uses radioactivity. By rights, she should be doing the radioactive survey, but Nancy doesn't fully trust her.

"How's it going?" Nancy asks cheerfully, her grainy alto raised so I can hear her over the roar of the fume hood.

"Not bad," I tell her. "Can't complain." I inject the fixative into the buffer in the coverslip chamber.

"You seem really perky lately," Nancy observes as she begins the tedious task of unscrewing the lids of all the vials. "Anything interesting going on?"

I reach for a second syringe, uncap the needle. "Actually, there is something interesting going on," I say mysteriously, full of my cocky, childish hubris.

"Yeah? What is it? Tell me."

I know immediately I shouldn't have said anything to Nancy. I draw the second fixative into the barrel of the syringe, then squirt it into the buffer solution, causing a brief, angry bubbling.

"You've got a girlfriend. I can tell."

"Maybe."

"You've been wearing that silly smile for more than two weeks now." Nancy finally gets to the last cap and places it beside the tray. She reaches to take one of the glass pipettes from a metal canister on the shelf at the back of the hood. "Where did you meet her?"

"Is it any of your business?" I shoot back, suddenly courageous.

"Just interested," she shrugs.

I cap the needle and start sealing the mouths of the fixative vials with plastic wrap. "At that writing class," I relent and tell her.

"So what's her name?"

"Angie," I answer, finishing up quickly so I can end the conversation.

"What's she like?" she asks, oblivious to my discomfort as she continues her work.

"She's a great poet."

"What kind of poetry?"

"I don't know. Kind of free association stuff, modern poetry." I'm losing my nerve now, uncomfortable talking about someone else with my ex.

"So tell me more," Nancy presses me as she pinches the valve on her pipette bulb to draw fluid into the pipette. "What does she do for a living? How old is she?"

"She's about thirty-five and works as a receptionist at an art gallery," I say impatiently.

Nancy fills the vials from left to right. "She must think you're brilliant," Nancy says, then turns and smiles at me. "So what more are you willing to tell me?"

"Talking might jinx it."

"I know you don't really believe that," she says, "but that's OK. I can't complain; it's just good to see you smiling again." Nancy's raised voice, her grainy alto, sings in my ears, the roar of the fume hood a background chorus. I marvel that she can still have this effect on me, even when I am talking excitedly about another woman. It's disturbing.

"Good luck," she says. "I just want you to be happy."

I walk away from her with a feeling of relief.

I switch the bathroom light off as I leave. At first, the glowing numbers of the digital alarm clock on the desk are all I can see: "1:15 AM" Gradually, my eyes adjust to the dark. The piece of paper reappears as a pale blue rectangle. The desk lamp's base shows a pale gray, almost egg white color and then the ghostly shapes of the rest of the furniture begin to form.

My breathing seems to echo off the walls as I walk to the bed and lower myself onto its far corner. The bedsprings squeal in unanimous protest.

A large window dominates the front wall. The breezy sound of a car speeding on wet pavement is accompanied by the gradual brightening of the dull red curtain. A dim trapezoid appears above the bed, tinctured a delicate pink. Shrinking and brightening as it slides onto the right wall, the mark accelerates toward the window as the whir of the car's wheels fills the room.

The light leaves, the sound gradually fades.

My inhalations are slow and steady, each exhalation a gentle rasp. I stand, prompting the bedsprings to squeal again and the telephone receiver to jiggle in its cradle.

I go to the desk and switch on the lamp. The chair croaks as I sit down. The paper sits in front of me, with the same three lines. I read it over.

Useless. I crumple it up and toss it into the small plastic wastebasket to the right of the desk.

I get another piece of paper from the drawer and slap it down in front of me. I quickly scribble "Dear Nancy," at the top left edge of the paper.

Stuck again, I put the pen down.

I am at the central lab bench.

I watch Nancy grasp the metal door handle with her left hand and shift her weight to pull the massive, smooth gray door open. The thin white cotton of her blouse is drawn against her skin, causing the straps of her brassiere to briefly materialize underneath.

Nancy steps aside to let the momentum carry the door open. Her olive green pants have pockets on either side, with a dark button holding down each flap. The right flap, though buttoned, is bunched unevenly at its top right corner to reveal a white piece of paper.

Nancy leaves, and I continue concentrating the diatom cells. The sounds of the pump dominate the room. The teeming liquid is down to about one centimeter and has become the color of milk chocolate. I tip the carboy forward and shake it so that the mouths of the two tubes inside, one intake and one output, fall into the collected liquid. I continue like this until the teeming liquid is almost gone, then I finally turn the pump off. The hissing of the ventilation system is now the only sound.

I lift the two tubes and allow them to drain, then transfer them into another carboy to my right. I set the first carboy aside on a metal cart for later and slide the second one into position. Once I've done all of the carboys, I'll combine everything into one large beaker for a final concentration until it becomes a dark, bitter chocolate brown, diatom-dense suspension.

I start the pump again and the grinding whir begins once more.

A loud snap breaks through the din. In my dazed state I jump, thinking something has gone wrong with the pump. But then, out of the corner of my eye, I see the thick metal handle of the door, a flattened "U" for an efficient grip, rotate one quarter of a turn. The heavy door swings in and Nancy strides through the doorway, past me without a word, and toward her office at the far side of the room.

As she passes the fume hood, I notice the right pocket of her pants. The flap is bunched unevenly at its top right corner, but there is nothing inside. So she's gone to see him.

Nancy disappears into her office. I wonder what it said.