I twisted my fork through the blueberry pie and wished it was apple. I’ve never been fond of blueberry, not even when the berries were wild and fresh from the forest. These were fresh from a can.

Barry’s Diner advertised itself as “home of the best blueberry pie in New York City.” That should have been the tip-off, but the sign outside said only Award-Winning Homemade Pie. So I’d come in hoping for a slice of fresh apple and found myself amid a sea of diners eating blueberry. Sure, the restaurant carried apple, but if everyone else was eating blueberry, I couldn’t stand out by ordering something different. It didn’t help that I had to accompany the pie with decaf coffee—in a place that seemed to brew only one pot and leave it simmering all day.

The regular coffee smelled great, but caffeine was off my menu today, so I settled for inhaling it as I nibbled the crust on my pie. At least that was homemade. I shifted on my seat, the vinyl-covered stool squeaking under me, the noise lost in the sounds of the diner—the clatter of china and silverware, the steady murmur of conversation regularly erupting in laughs or shouts. The door behind me opened with a tinkle of the bell, a gust of October air and a belch of exhaust fumes that stole that rich scent of fresh coffee.

A man in a dirt-encrusted ball cap clanked his metal lunch box onto the counter beside my plate. “He got another one last night.Number four. Police just confirmed it.”

I slanted my gaze his way, in case he was talking to me. He wasn’t, of course. I was invisible . . . or as close to it as a nonsuperhero could get, having donned the ultimate female disguise: no apparent makeup and thirty-five pounds of extra padding.

“Who’d he get this time?” the server asked as she poured coffee for the newcomer.

“Little old Chinese lady closing up her shop. Choked her with a wire.”

“Garroted,” said a man sitting farther down the counter.

“Gary who?”

The other man folded his newspaper, rustling it with a flourish. “Garroted. If you use something to strangle someone, it’s called garroting. The Spanish used it as a method of execution.”

I glanced at the speaker. A silver-haired man in a suit, manicured fingernails resting on his Wall Street Journal. Not the sort you’d expect to know the origin of the term “garroted.” Next thing you know, his neighbors would be on TV, telling the world he’d seemed like such a nice man. They continued talking. I struggled to ignore them.

Had to ignore them. I had a job to do, and couldn’t allow myself to be sidetracked.

It wasn’t easy. Words and phrases kept tumbling my way. Killer. Victim. Police. Investigation. No leads. I could, with effort, block the words, remind myself that they had nothing to do with me, but the voices weren’t so easy to push aside. Sharp with excitement, as if this was something they’d seen in a movie and the victims were nothing more than actors who, when the credits rolled, would stand up, wash off the fake blood and grab a cigarette before heading home to their families.

The Helter Skelter killer. Even the name was catchy, almost jocular. I bet he was proud of it. He’d risen from the ranks of the unnamed and now he was someone—the Helter Skelter killer. I pictured him sitting in a coffee shop like this, eavesdropping on a conversation like this one, his heart tripping every time he heard his new name.My hand tightened on my fork. A burr on the handle dug in. I squeezed until pain forced my thoughts back on track.

It wasn’t my concern. There were dozens of killers all across the continent, plotting crimes just as ruthless. Nothing to be done about it, and I was no longer in a position to try.

I took a swig of coffee. Bitter and burned, foul on my tongue, acid in my stomach. I took another gulp, deeper, almost draining the mug. Then I pushed it aside with my half-eaten pie, got to my feet and walked out.

I stood in the subway station and waited for Dean Moretti. Moretti was a Mafia wannabe, a small-time thug with tenuous connections to the Tomassini crime family. Three months earlier, he had decided it was time to strike out on his own, so he’d made a deal with the nephew of a local drug lord. Together they’d set up business in a residential neighborhood previously untapped—probably because it was under the protection of the Riccio family.

When the Riccios found out, they went to the Tomassinis, who went to the drug lord, who decided, among the three of them, that this was not an acceptable entrepreneurial scheme. The drug lord’s nephew had caught the first plane to South America and was probably hiding in the jungle, living on fish and berries.Moretti wasn’t so easily spooked, which probably speaks more to a lack of intelligence than an excess of nerve.

While I waited for him, I wandered about the platform, taking note of every post, every garbage can, every door- way. Busywork, really. I’d already scouted this station so well I could navigate it blindfolded, but I kept checking and double-checking.

My stomach fluttered. Not fear. Anticipation. I kept moving, trying to work past it. There was no more room here for anticipation than there was for fear. It was a job. It had to be approached with cool, emotionless efficiency. You cannot enjoy this work. If you do, you step onto the fast slide to a place you’ll never escape, become something you swore you’d never be.

I kept my brain busy with last-minute checks. There was one security camera down here, but an antiquated one, easy to avoid. I’d heard rumors of post-9/11 upgrades, but so far, this station had avoided them. Though I hadn’t seen a uniformed transit cop, I knew there could be a plainclothes one, so I spotted the most likely suspects and stayed out of their way. Not that it mattered—in addition to the extra padding I was wearing a wig, colored contacts, eyeglasses and makeup to darken my skin tone.

I’d spent three days watching Moretti, long enough to know he was a man who liked routines. Right on schedule, he bounced down the subway steps, ready for his train home after a long day spent breaking kneecaps for a local bookie.

Partway down the stairs he stopped and surveyed the crowd below. His gaze paused on anyone of Italian ancestry, anyone wearing a trench coat, anyone carrying a bulky satchel, anyone who looked . . . dangerous. Too dumb to run, but not so dumb that he didn’t know he was in deep shit with the Tomassinis. At work, he always had a partner with him. From here, he’d take the subway to a house where he was bunking down with friends, taking refuge in numbers. This short trip was the only time he could be found alone, obviously having decided that public transit was safe enough.

As he scouted the crowd from the steps, people jostled him from behind, but he met their complaints with a snarl that sent them skittering around him. After a moment, he continued his descent into the subway pit. At the bottom, he cut through a group of young businessmen, then stopped beside a gaggle of careworn older women chattering in Spanish. He kept watching the crowd, but his gaze swept past me. The invisible woman.

I made my way across the platform, eyes straining to see down the tunnel, pretending to look for my train, flexing my hands as I allowed myself one last moment of anticipation. I closed my eyes and listened to the distant thumping of the oncoming train, felt the currents of air from the tunnel.

It was like standing in an airplane hatch, waiting to leap. Everything planned, checked, rechecked, every step of the next few minutes choreographed, the contingencies mapped out, should obstacles arise. Like skydiving, I controlled what I could, down to the most minute detail, creating the ordered perfection that set my mind at ease.Yet I knew that in a few seconds, when I made my move, I left some small bit to fate.

I inhaled deeply and concentrated on the moment, slowing my breathing,my pulse. Focusing.

No time to second-guess. No chance to turn back. At the squeal of the approaching train, I opened my eyes, unclenched my hands and turned toward Moretti.

I quickened my pace until I was beside him. Tension blew off him in waves.His right hand was jammed into his pocket, undoubtedly fondling a nice piece of hardware.

The train headlights broke through the darkness. Moretti stepped forward. I stepped on the heel of the woman in front of me. She stumbled. The crowd, pressed so tightly together, wobbled as one body. As I jostled against Moretti,my hand slid inside his open jacket. A deft jab followed by a clumsy shove as I “recovered” my balance. Moretti only grunted and pushed back, then clambered onto the train with the crowd.

I stepped onto the subway car, took a seat at the back, then disembarked at the next stop, merging with the crowd once again.