Suddenly it stopped. Lilly glanced back at the wall opposite the door, and saw a passageway. A small door in the middle of the wall.

Lilly rubbed her eyes and looked again. She was not hallucinating.

No way it had been there before. Cautiously approaching, Lilly stopped at the door first, listened to the hallway. Still quiet. A loud noise made her jump.

The passageway was gone. Closed up.

She felt along the paneled wall, but there was no catch, no seam. It had vanished.

IT TOOK HER TEN MINUTES to figure out the sequence of events that led to the noise and the revelation of the door in the wall.

She had been sitting on the edge of the nightstand, her feet on the floor. She had reached over and pushed on the edge of the painting.

She did it all again, exactly the same way. A few seconds later the panel raised, and there was the little door again. It seemed to lead into a dark room, a dark space, a dark corridor, but none of that really mattered to Lilly. What mattered was that it was big enough for her to crawl through.

This time, she did not hesitate.

Before the panel could slide shut again, she crossed the room. She propped her shoes in the opening, entered the portal, and slipped into the blackness beyond.

SEVENTY-FOUR

1:40 AM

TANGRAM PUZZLES WERE five triangles, one square, and one parallelogram. According to the book, these pieces could be arranged into a virtually endless number of shapes. If the Collector was making a tangram puzzle out of the rooftops of North Philadelphia, which problem was he using?

All four of the crime scenes were corner buildings—essentially triangles. A parallelogram could be seen as a diamond. If their theory was correct, it would leave one more triangle, one square, and one diamond. If they could piece together the first four crimes scenes in some sort of a coherent order, based on their geographic location and relevance to each other—in an order that corresponded to a particular tan-gram problem—they might be able to predict the location of the next three. It was a huge long shot—but at the moment it was all they had.

Byrne raised Josh Bontrager and Dre Curtis on the radio. They needed more eyes on this.

BYRNE STARED AT THE SCREEN, at the map, his eyes roaming the shapes of the buildings, their relationships to one another. He closed his eyes for a moment, recalling the puzzle pieces in Laura Somerville’s apartment, the feel of the ivory.

Moments later, Bontrager and Dre Curtis pulled up, exited their car.

“What’s up?” Bontrager asked.

Byrne gave them a quick rundown. Bontrager reacted with a young man’s enthusiasm for the theory. Curtis, although accepting, was more skeptical.

“Let’s hear some ideas,” Byrne said. “Some words or concepts that might apply. Something that might relate to the puzzle he’s making.”

“He’s a magician,” Bontrager said. “An illusionist, a conjuror, a trickster.”

Jessica reached into the back of the car. She retrieved the three books by David Sinclair that Byrne had purchased from Chester County Books. She opened the book of tangram and began to run through the index. There were no problems that related to magicians.

“Cape, wizard, wand, top hat,” Curtis said. “Cards, coins, silks.”

Jessica flipped pages of the index, shook her head. “Nothing even close.”

“How about a castle?” Bontrager asked. “Isn’t there a Magic Castle somewhere?”

“Here’s a castle,” Jessica said. She found the page in short order, flipped the book open. The tangram problem, in silhouette, looked to be a tall pagoda, with a tiered tower and multiple eaves. If the first four crime scenes represented the bottom of the problem, it could not be this diagram. There had to be at least two triangles at the top.

“What about the illusions themselves?” Curtis asked. “The Sword Box, the Garden of Flowers, the Water Tank?”

Jessica scanned the index again. “Nothing like that.”

Byrne thought for a moment, poring over the map. “Let’s work backwards. Let’s start with the shapes themselves, see if they match a pattern.”

Jessica tore the center section from the book, handed each of the other detectives ten or so pages of problems. They gathered around the map they had received from Hell Rohmer, eyes searching, matching shapes. Every so often, each of the detectives glanced at their watches. Time was passing.

BYRNE STEPPED AWAY from the car. Rain fell again. The other detectives grabbed everything from the car, crossed the street, and entered an all but empty twenty-four-hour diner called Pearl’s. They set up on the counter in front of an apprehensive fry cook.

Soon after, Byrne walked in. He finger-walked his notebook, finding David Sinclair’s cell phone number, and punched it in. Sinclair answered. Identifying himself, Byrne apologized for the late hour. Sinclair said it was fine, he was awake.

“Where are you?” Byrne asked.

“I’m in Atlanta. I have a book signing tomorrow.”

“Do you have e-mail access right now?”

“I do. I’m in my hotel room. They have high-speed access here. Why, do you want to—”

“What’s your e-mail address?”

David Sinclair gave it to him.

“Can you hang on one minute?” Byrne asked.

“Sure.”

Byrne raised Hell Rohmer on the handset. He gave him David Sinclair’s e-mail address. “Can you make a composite of the four buildings, and outline them in some way?”

“I’ll drag it into PhotoShop and put a red line around the edges. Will that work?”

“That’ll work,” Byrne said. “Can you save it as a file and e-mail it to this guy?”

Byrne gave him the address.

“I’m on it,” Hell said. “Shouldn’t take more than two minutes.”

Back on his cell, Byrne told David Sinclair to expect the file.

“If you don’t get the file in five minutes, I’d like you to call me back at this number,” Byrne said. “I’ll also give you a second number if, for some reason, you don’t reach me.” Byrne gave the man his and Jessica’s cell numbers.

“Got them. One question.”

“Go.”

“This is about the breaking news story out of Philly, isn’t it? It’s on CNN.”

There was no point in dancing around it. They needed this man’s help. “Yes.”

Sinclair was silent for a few moments. Byrne heard him draw a deep breath, release it. “Okay,” he said. “One more question.”

“I’m listening.”

“What exactly am I looking for?”

“A developing pattern,” Byrne said. “A problem. A tangram problem.” “Okay. Let me look at it. I’ll get back to you.”

Byrne clicked off. He turned his attention to the man behind the counter. “You have today’s paper?” he asked the wide-eyed fry cook.

No response. The man was all but catatonic.

“The paper. Today’s Inquirer?”

The man slowly shook his head. Byrne looked to the back of the diner. There was only one customer. He was reading the Daily News. Byrne stormed to the rear, grabbed it out of the man’s hands.

“Hey!” the man said. “I was reading that.”

Byrne dropped a five on the table. If everyone got out of this alive he would consider it a bargain. He handed each of the detectives a pair of sheets and a pair of shapes to create. He kept one. In a few moments they had all seven shapes.

Josh Bontrager’s cell phone rang. He stepped outside.

Byrne put the pieces on the floor. Five triangles, one square, one diamond. Jessica put the torn pages from the tangram book along the length of the counter.

Page after page of tangram problems, all categorized by country of origin and puzzle designer. There were jewelry, vessels, tools, animals, musical instruments, buildings. One page was devoted to plants. Another to mountains.