He had put the towels in the laundry and forgotten to replace them. So he threw on his terry cloth robe, wiped his feet on the bath mat, and padded down the hallway to the linen closet.

He lived in a two-story condo in a five-story Back Bay brownstone. The master bedroom and attached study were at the front. The guest/TV room was at the rear. The linen closet was in the hallway between.

He opened the door, grabbed a thick towel, and decided that since he was so close, he would surrender to temptation. He would visit his sanctum sanctorum.

It always cheered him when he needed cheering, and since the wedding that wasn’t, he’d needed plenty. If business was slow, it reminded him of his assets. And when he questioned himself altogether, when he wondered if he should have pursued some sane profession like business or law rather than brokering rare books and documents, a visit to the sanctum sanctorum reminded him that what he did mattered.

He knelt and pressed a sequence of floor tiles in the linen closet; then he gripped the doorframe on either side and pulled. With a hydraulic whoosh, the whole closet slid out of the wall and pivoted into the hallway.

In front of him now was a stainless steel door with a combination lock.

He spun the dial, and the door opened. The space beyond was not much wider than the linen closet, not much deeper than the shower stalls in the bathrooms on either side. Walls, floor, and ceiling were steel lined. Temperature and humidity were strictly controlled. And in case of fire, the room would fill with halon gas to kill the flames and preserve the contents.

He kept most of his collection in the Antiquaria office on Newbury Street, where he did the daily work of buying and selling everything from Shakespeare Second Folios to signed first editions of the complete James Bond. But here was where he kept the things that mattered most, the treasures he hoped never to part with until the time came to bequeath them to his son or give them to the Massachusetts Historical Society.

Aside from his contractor brother, who had installed this room, the only people who knew about it were Evangeline and his silent partner, Orson Lunt.

He flipped on the lights. To the left was a wall of tray-type stainless filing cases, all alphabetized. The S drawer held a quarto of Shakespeare’s Love’s Labor’s Lost, printed in 1598. In the W file was George Washington’s letter of March 5, 1775, ordering the army to go on to Dorchester Heights.

And when Peter pulled out the L file, he was looking into the eyes of Abraham Lincoln, forthright, confident, careworn. The picture had been taken by Alexander Gardner in November 1863, a few weeks before the Gettysburg Address. It had been printed on a carte de visite and signed by Lincoln himself. As far as Peter knew, it was one of only a few authentically signed Lincoln cartes in existence.

But the real treasure lay to the left of the picture.

In 1864, Lincoln had signed forty-eight printed copies of the Emancipation Proclamation, to be auctioned at a Philadelphia fund-raiser for the United States Sanitary Commission. They were known as the Leland-Boker editions, after the printer, and only half were known to exist. Peter Fallon was looking at one of them.

He would be the anonymous donor at his own show, and he would insist on high security. After all, Robert F. Kennedy’s signed Leland-Boker had recently sold for $3,700,000, the most money ever paid for a presidential document. Peter and Orson Lunt had bought theirs from an Illinois dentist in 1990 for $300,000. It was not as valuable as Kennedy’s, nor as good a deal. Kennedy had paid only $9,500 for his in 1961, and the Kennedy name had given it a provenance that added a premium to any price.

In the humming quiet of the secret room, Peter studied the single column of type and the confident signature, A. Lincoln. In the Emancipation Proclamation, Lincoln had decreed that those who had been held in bondage for generations would “be then, thenceforward, and forever free” … at least in the rebellious states. He had not freed the slaves in loyal states, because he did not believe the Constitution gave him that right, and he feared that they would secede if he tried, but he had taken the first step toward racial equality in America.

Peter considered it an act of enormous moral and political courage.

After the Proclamation, the war was no longer a struggle between the ideologies competing in America since its birth, between those who wanted a strong central government and those who wished, as Jefferson Davis had said, simply “to be left alone.” Lincoln had transformed the war into a struggle over the very meaning of America.

But like so many in those days, Lincoln would pay for his beliefs with his life.

Peter glanced at the document to the right of the Gardner photograph, one of the most poignant letters ever penned in America.

A surgeon named Curtis, of the U.S. Army Medical Corps, had written it to his mother in April 1865.