She approached this search the same way Rhyme had taught her to run a crime scene: looking over the whole first, then organizing a logical plan, then executing the search. Sachs first separated the material into four stacks: general information, West Side history and Gallows Heights, civil rights in the mid-1800s and Potters’ Field. She started on the graveyard first. She read every page, confirmed Charles Singleton’s reference to his regiment’s being mustered at Hart’s Island. She learned how the graveyard came into being, and how busy it had been, especially during the cholera and influenza epidemics of the mid- and late-nineteenth century, when cheap pine coffins would litter the island, stacked high, awaiting burial.

Fascinating details, but not helpful. She turned to the civil rights material. She read a mind-numbing amount of information, including references to the Fourteenth Amendment controversy but nothing that touched on the issues Professor Mathers had suggested to them as a motive for setting up Charles Singleton. She read in an 1867 New York Times article that Frederick Douglass and other prominent civil rights leaders of the time had appeared at a church in Gallows Heights. Douglass had told the reporter afterward that he had come to the neighborhood to meet with several men in the fight for the amendment’s passage. But this they already knew, from Charles’s letters. She found no mention of Charles Singleton but did come across a reference to a lengthy article in the New York Sun about the former slaves and freedmen who were assisting Douglass. That particular issue, though, was not in the archives.

Page after page, on and on…Hesitating sometimes, worrying that she’d missed those vital few sentences that could shed light on the case. More than once she went back and reread a paragraph or two that she’d looked at without really reading. Stretching, fidgeting, digging at her fingernails, scratching her scalp.

Then plowing into the documents once more. The material she’d read piled up on the table but the pad of paper in front of her held not a single notation.

Turning to New York history, Sachs learned more about Gallows Heights. It was one of a half-dozen early settlements on the Upper West Side of New York, separate villages really, like Manhattanville and Vandewater Heights (now Morningside). Gallows Heights extended west from present-day Broadway to the Hudson River and from about Seventy-second Street north to Eighty-sixth. The name dated from colonial times, when the Dutch built a gallows atop a hill in the center of the settlement. When the British purchased the land, their hangmen executed dozens of witches, criminals and rebellious slaves and colonists on the spot until the various sites of justice and punishment in New York City were consolidated downtown.

In 1811 city planners divided all of Manhattan into the blocks that are used today, though for the next fifty years in Gallows Heights (and much of the rest of the city) those grids could be found only on paper. In the early 1800s the land there was a tangle of country lanes, empty fields, forests, squatters’ sheds, factories and dry docks on the Hudson River, and a few elegant, sprawling estates. By the mid-nineteenth century Gallows Heights had developed a multiple personality, reflected in the map that Mel Cooper had found earlier: The big estates existed side by side with working-class apartments and smaller homes. Shantytowns infested with gangs were moving in from the south, on the tide of city sprawl. And – just as crooked as street thieves, though on a larger and slicker scale – William “Boss” Tweed ran much of the corrupt Tammany Hall Democratic political machine from the bars and dining rooms in Gallows Heights (Tweed was obsessed with profiting from the development of the neighborhood; in a typical scheme the man pocketed $6,000 in fees for the sale to the city of a tiny lot worth less than $35).

The area was now a prime Upper West Side neighborhood and among the nicest and most affluent in the city, of course. Apartments were going for thousands of dollars a month. (And, as an irritated Amelia Sachs now reflected from her “small crime scene” dungeon, the present-day Gallows Heights was home to some of the best delis and bagel bakeries in the city; she hadn’t eaten today.)

The dense history reeled past her but nothing bore on the case. Damnit, she ought to be analyzing crime scene material, or better yet, working the streets around the unsub’s safe house, trying to find some connections to where he lived, what his name was.

What the hell was Rhyme thinking of?

Finally she came to the last book in the stack. Five hundred pages, she estimated (she was getting a good eye by this point); it turned out to be 504. The index didn’t reveal anything important for the search. Sachs skimmed the pages but finally could take it no longer. Tossing the book aside, she stood, rubbed her eyes and stretched. Her claustrophobia was kicking in, thanks to the suffocating ambiance of the archives, located two flights underground. The foundation may have been renovated last month but this place was still the original basement of the Sanford Mansion, she supposed; it had low ceilings and dozens of stone columns and walls, making the space even more confining.

That was bad enough but the worst was the sitting. Amelia Sachs hated to sit still.

When you move they can’t getcha…

No small crime scenes, Rhyme? Brother…

She started to leave.

But at the door, she paused, looking back over the material, thinking: A few sentences in one of these musty books or yellowing newspapers could make the difference between life and death for Geneva Settle – and the other innocents that Unsub 109 might one day kill.

Rhyme’s voice came back to her. When you’re walking the grid at the scene, you search it once and then again and when you’re finished, you search it once more. And when you’re done with that, you search it again. And…

She glanced at the last book – the one that had defeated her. Sachs sighed, sat back down, pulled the 504-pager toward her and read through it properly and then flipped through the photographs in the middle.

Which, it turned out, was a good idea.

She froze, staring at a photograph of West Eightieth Street, taken in 1867. She gave a laugh, read the caption and the text on the opposite page. Then pulled her cell phone off her belt and hit speed-dial button 1.

“I found Potters’ Field, Rhyme.”

“We know where it is,” he snapped into the microphone near his mouth. “An island in the -”

“There’s another one.”

“A second cemetery?”

“Not a cemetery. It was a tavern. In Gallows Heights.”

“A tavern?” Well, this was interesting, he thought.

“I’m looking at the photo, or daguerreotype, whatever it is. A bar named Potters’ Field. It was on West Eightieth Street.”

So, they’d been wrong, Rhyme reflected. Charles Singleton’s fateful meeting may not have been on Hart’s Island at all.

“And, it gets better – the place burned down. Suspected arson. Perpetrators and motive unknown.”

“Am I right in supposing that it was the same day Charles Singleton went there to – what did he say? To find justice?”

“Yep. July fifteenth.”

Forever hidden beneath clay and soil…

“Anything else about him? Or the tavern?”

“Not yet.”

“Keep digging.”

“You bet, Rhyme.”

They disconnected the call.

Sachs had been on the speakerphone; Geneva had heard. She asked angrily, “You think Charles burned that place down?”

“Not necessarily. But one of the major reasons for arson is to destroy evidence. Maybe that’s what Charles was up to, covering up something about the robbery.”

Geneva said, “Look at his letter…he’s saying that the theft was set up to discredit him. Don’t you think he’s innocent by now?” The girl’s voice was low and firm, her eyes bored into Rhyme’s.