"Text that to me," said Agent Bell. "I'll get it circulated to everyone here."

Someone with a bullhorn in the park called out, "No justice, no business! No justice, no business!" The crowd picked it up and chanted it back. "c.r.a.p," said Callan. "What time are they scheduled to move?"

Commander McMains said, "In thirty minutes, at nine o'clock." Hearing the time nudged Heat to make a scan of the area, wondering if Glen Windsor lurked out there and, if he did, what he had in mind. They gathered around a map as McMains unfurled it on the hood of a nearby patrol car. "Their permit calls for a parade from where they are now, proceeding up Broadway, and terminating at City Hall Park."

"Side streets?" asked the special agent.

"All closed. And we have pipe barricades to keep them off the sidewalks. I've also closed the Four and Five subway station to cut off new arrivals." McMains took a ballpoint from his uniform chest pocket and drew brackets mid-route. "Most of our a.s.sets are set up here to keep them from getting any ideas about taking over Wall Street or Exchange Place." Just as the commander voiced the notion, the "No justice, no business! No justice, no business!" chant punctuated it.

Callan closed his eyes as if having a conversation with himself. Then he clapped his hands together once and said, "That's where we put everything. Wall Street is the vulnerable part of the whole circus. If that virus gets released up there, we're not only talking ma.s.s casualties, a quarantine would shut down the New York Stock Exchange, maybe even the Federal Reserve Bank. Can you imagine the ripple effects of that?"

"Let's not," said Agent Bell.

Since n.o.body had spotted the Boz Brigade fire wagon, not even the choppers, Callan and McMains formed a plan to hustle agents and uniforms up the route of the march and throughout the Wall Street financial blocks to check parking lots and garages for the vehicle. All the detectives from Heat's squad had arrived and would join her on the search, as well.

"And do not tell me I have to wait in the car," said Rook.

Heat replied, "I won't. Because you're going to stay here."

"You really think I'm going to be in the way?"

"Not really. But I don't want you up there if something bad comes down. We have it covered, end of discussion."

"I'll be fine, I have this." He held a gas mask over his face and breathed loudly. "Luke, I am your fa-"

She pulled the mask away. "You're staying here." Then she left with the others.

Rook stood off moping to the side of the staging area and watched a contingent of uniforms in riot gear and gas masks attempt to form a containment barrier with orange plastic netting while a lieutenant addressed the crowd, asking them to stop the march and disperse for their own safety. They drowned him in boos.

At nine sharp, an organizer raised an air horn and gave it a long blast. Cheers erupted and the mob moved forward, slowly pushing past the lines of police for the march up Broadway.

Some of the protestors, schooled in civil disobedience tactics, threw themselves down and linked arms on the ground to form a barrier between the pa.s.sing crowd and the police who were attempting to contain them. As the cops advanced to deal with the human chain, Rook decided he didn't like his proximity to the flailing and shouting and drifted across the street into the park, circling around the mob toward the rear of the action.

He pa.s.sed a Statue of Liberty street mime, a "living statue" in turquoise greasepaint. In a Chinese accent Lady Liberty hawked a souvenir pose with him for only ten dollars. As he walked on, the asphalt path Rook followed curved through the park to Castle Clinton, the sandstone fort built as a cannon battery to protect Manhattan from the British in the War of 1812. Port-a-johns set up for the protest lined the castle's north wall near overflowing trash cans and about two dozen stragglers who had decided sharing some choice weed held more allure than a long walk. He came upon some plastic tubs filled with melted ice and a few unclaimed bottled waters floating between the cubes. His tongue still felt furry after the long night, so he helped himself to one while he leaned against the castle and watched the rear flank of the march shuffle uptown.

About four blocks away, two NYPD helicopters hovered at different alt.i.tudes over the skysc.r.a.pers of the Financial District. He felt the sun on his face and listened to their engine hums mix in with the bullhorn shouts and the chorus of chants. Off to his right, he heard a sound like a large flag fluttering. But when he turned, he saw it was just someone pulling the white fabric flap aside to open the covered first aid tent. He watched the choppers some more, envisioning Heat and the others underneath them, sweeping those streets and checking garages, and wishing he could be part of the action. But then another noise coming from that tent drew his attention.

Rook heard a whinny.

Hoof clops came next, and a draft horse ambled out of the large white event tent. Rook dropped his bottle of water and already had his cell phone out by the time the red Boz Brigade cart rolled into view behind the horse and stopped. A man walked out of the tent on the far side, blocked by the carriage. But the limp visible under the cha.s.sis told Rook all he needed for confirmation.

Nikki answered her phone without a h.e.l.lo. "No, Writer Boy, you still have to stay put."

"He's here," he said in a whisper.

"Where?"

"Castle." And as soon as Rook said it, the serial killer climbed up, stood on the coachman's step, and made eye contact. "Rainbow."

Up on Whitehall Street, Nikki held her phone away from her ear, about to tell Agent Callan about Rook's sighting, when their radios came alive with calls from both choppers. "Red fire wagon in sight." And "Got it. Castle in the park."

Heat didn't wait. She sprinted to a blue-and-white idling at the curb, yanked open the pa.s.senger door, and said, "Hit it."

Glen Windsor's gunshot wound slowed him down getting both legs up and into the driver's box. He kept his eyes on Rook the whole way and even gained some time as the writer hesitated when he looked inside the tent. Sprawled on the ground there, the bodies of two jihadist volunteers bled out from neck slashes. They were martyrs, all right, thought Rook. Just for a different cause-a cause that was not their own. He turned away from the pair of dead men and ran toward the fire wagon. Windsor dismissed him until he saw Rook make the smart move, angling for the horse, not him, so he quickly s.n.a.t.c.hed up the reins, gave them a snap, and the big animal started off.

The sergeant at the wheel knew which back streets had been cleared as emergency lanes, so he and Nikki flew until they got to the entrance of Battery Park. A band of protestors locked arms and blocked the car, laughing and hurling insults. Heat bolted out and ran, leaving the door open as she wove through the crowd.

Rainbow clucked to get the horse moving so he could catch up with the marchers. He twisted in the coachman's seat to do a shoulder-check for Rook, and was surprised when he couldn't locate him back near the white tent. Then the carriage jolted and the suspension iron groaned under a sudden weight. Windsor pivoted more. As the wagon rolled across the meadow, he peered around the copper boiler full of virus behind his seat, and saw a hand come up over the boot. Then he glimpsed Jameson Rook, hoisting himself up on the back of the carriage and crawling toward him.

He jerked the reins and pulled the brake handle, trying to lurch Rook off with a sudden stop. But it only thrust him closer to Windsor as he held on. Then Rainbow went to the whip, and Rook almost fell backward as the horse reacted and yanked the fire wagon forward toward the great lawn, scattering panicked stragglers as it thundered ahead.

The wide belly of the boiler presented the greatest obstacle. As the carriage bounced and swayed, Rook had to climb slightly outboard to get around it. At his most vulnerable spot, Windsor lashed him with the whip. But Rook grabbed it on one of his wild thrashes, pulling it away.

Galloping across the pasture, closing in on the rear field of marchers, Windsor reached for an orange electrical cable draped over the dash rail in front of him. Rook's heart sank when he saw the grip device dangling at the end of it. He knew that would be The Switch: the release b.u.t.ton for the spray. He visually traced the wire to where it came out of the seat back and snaked up between the copper steam tubing to the valves on the boiler vat, then to the modern set of plastic aerosol nozzles beside his head on the chimney.

Rook yanked at it. The cord wouldn't budge from the mechanism.

He glanced up front. Windsor had hold of the cable. The switch was nearly in his hand.

Nikki Heat fought her way out of the back of the crowd, drew her Sig, planted her left knee on the gra.s.s, and combat-braced on her right, drawing aim at the fire wagon charging toward her. She had to be careful not to hit the horse. The animal was not only an innocent, but if it dropped, it could topple the carriage and spill the virus. The same caution held for the vat. She had to wait for an angle of fire that wouldn't risk puncturing the copper boiler if she missed Windsor or if the slug went through him.

She saw him going for the switch on the orange cable and wondered if she should just take the shot. That's when Rook pounced on top of Windsor and clawed over his shoulders for the b.u.t.ton. Heat holstered up and sprinted for the carriage.

Rook's lunge knocked the cable out of Windsor's hand. He let go of the reins and bent down into the well of the coachman's box to retrieve it. While the undriven horse began to run a circle in the meadow, with screaming protestors diving for safety, Rook clambered to drape himself over Rainbow, reaching down past him to get the switch out of play. When Windsor came inches from getting to the end of the cable, Rook switched tactics. He balled a fist and started pounding the fresh gunshot wound. Rainbow shrieked in pain but held fast to the wire. Rook punched his calf again and again. Windsor twisted to punch Rook, and when he did, Rook s.n.a.t.c.hed the cable from him and tossed the deadly end of it over the back of the seat, where it dangled out of reach.

Rainbow removed his hands from his bleeding calf and elbow-smacked Rook's nose. As Rook fell to the side, Windsor pulled his knife from a belt sheath. Through watering eyes, Rook caught the glint of the blade and swung his forearm up. Just as he made contact with Rainbow's wrist, the carriage double-b.u.mped over the stone curbing of the park path and the combination flung the knife out of the killer's hands and onto the pa.s.sing ground. Unarmed and desperate, Windsor hurled himself up, bending over the back of the seat rail, groping to reach the swaying cable. But the fire carriage lurched again as Heat caught up and leaped aboard. She s.n.a.t.c.hed Windsor by the back of his belt and shoved him headfirst right over the seat. He fell into the gap of air between the coachman's box and the boiler, landing hard on the ground speeding underneath. The wagon shuddered as the rear wheels rolled over him. Nikki jumped off.

Sniffing back blood, Rook grabbed the cable and drew it safely into the coach. He called a soft "Whoa" and tugged the reins. The horse came to a docile stop amid hundreds of marchers. Across the lawn he could hear Rainbow, facedown in the gra.s.s, pleading to Heat who stood above him. "Shoot me! Aw, f.u.c.k, please, just f.u.c.king do it!"

But not all destinies are fulfilled. Nikki ended the killing right there. She cuffed him, holstered her gun, and waited for the rest of the crew to catch up while Rook neatly coiled the orange cord.

And then under the thrum of hovering airships and the urgent wail of sirens, a strange and graceful quiet enveloped her, as if mayhem's shadow had been carried away on the spring breeze off the harbor. In her soundless world cushioned by deliverance, Nikki looked around at all the faces in the crowd, at all the people who were going to live. And looking down at Rainbow, she knew she was going to live, too.

Ten years, twenty-three weeks, and four days of agony, apprehension, and dread-all over in a single moment. She reflected on that decade-plus. Her entire adult life had been honed by loss, faith, preparation, sacrifice, and tenacity. But also by fortune. A deadly plot might have been fulfilled if it hadn't been for a serial killer getting himself involved.

And if Detective Heat hadn't been juggling both cases.

Monday evening Nikki came home from the federal arraignment of Carey Maggs feeling relief and agony. When Rook called from his suite at the SLS in Beverly Hills to check in on her, she said, "You know, everyone says there's no such thing as closure. But I'm starting to learn I'm not so much interested in that as I am in a finish. I expect it's natural that I'll carry this hurt about my mom all my life, but I sure wouldn't mind having the work of it end."

"And Maggs pleading not guilty keeps it in your face."

"Absolutely. Months and more of trial and delays. I want to be done, Rook."

"At least the investigation part is."

"There's that," she said. "You should have seen him today with his Dream Team of legal heavyweights. It looked like he was sitting there with Mount Rushmore."

"The feds are still going to nail him, you know that."

"But it won't be without a long fight. His team already has pet.i.tioned to throw out the corroborative testimony from Glen Windsor's confession. They're calling it fruit from a tainted tree."

"I hate that," said Rook. "What has this country come to when you can't trust the word of a serial killer?"

"I'd laugh if it weren't true. I've been involved in enough cases to know how this will work, too. The prosecutor will trade that away if the defense doesn't pursue DHS taking Maggs off for his extracurricular interrogation."

"They do have a Black Barn, I know it."

"So tell me about your meetings. Is your head swimming with fruit-basket love?"

"Truthfully, Nik, it all feels sort of empty. I mean, after single-handedly saving the world as I did."

She chuckled. "Yeah, maybe you, Batman, and Lone Vengeance should form a support group."

"Sure, we could call it... I dunno... Cape-Anon. Although, superheroes are generally anonymous already, so it would have to be Cape-Anon-Anon."

"Good night, Rook."

"Good night? But you got my Spidey sense all tingly."

"Hold that thought."

Home alone with no obligations after a harrowing few weeks, and a deep fatigue she thought she would never sleep off, Nikki contemplated an evening of scented candles, bubble bath, and soulful divas on the boom box. But that felt like distraction; more superficial than the inner healing she craved.

Besides, she knew she could never relax with missing pieces or loose ends.

She brought out the cardboard tube and set it on the coffee table. Puzzle Man, however unnerving a partner, had proved his worth and managed to crack the code. The message felt incomplete, but with the arrest of Carey Maggs as the leader of the conspiracy, Heat told herself to let it go.

But she couldn't.

Back to her mom. Back to lack of closure.

Why, she wondered, would someone work so hard to construct a coded message that, essentially, didn't reveal information? Her mother was more practical than that. No wasted effort, everything for a purpose. The apple didn't fall far.

Nikki slid the papers out of the tube and laid them out before her. Then she stacked them and held them to the light, getting the same message as before: Unlock the Dragon.

As she had done, ad nauseam, she considered the significance of each word. Nikki focused on "Unlock" because that felt like a call to action-one she hadn't taken. That's what kept her persevering. Nikki had not unlocked anything.

She had spent eleven years going around that apartment searching for locks or secret boxes. Her father had let her go through some of their things that he had brought to his condo in Scarsdale, and she had found nothing there. So no more house searches.

Heat stared at the message until her eyes glazed. Then she spread the four pages apart, kicking herself for going back to square one like that. But she did.

Why was this so difficult? What had Puzzle Man said? That the hardest code to crack was the one that's only known by two people? The sender and the receiver.

If Nikki were the intended receiver, she wondered, why choose her? When her mother was murdered, Heat was a theater student at Northeastern, not a cop, and with no hint of becoming one. Or maybe her mom knew more about her nature than she did. Or simply trusted her completely.

"So, Mom," she said aloud, "what's just between us here?"

She tried not to picture the mother of her nightmares sprawled on the kitchen floor. Her gaze fell across the room, and the ghost of her recent dream came to her: Cynthia playing the piano in the corner, saying, "You know..."

It began to seep through as she laid her eyes on the four pages again. Nikki removed her focus from the coded marks themselves and contemplated the sheet music they had been written on. A recollection drifted to her on a trail of time's smoke.

Those four pieces comprised one of Nikki's piano recitals when she was sixteen. She rushed to the piano bench and dug out the old program. There they were on the list. Those four songs, and no others.

Why choose them for the code?

That recital lived clearly in her memory. She recalled her stage fright, and making only one mistake in her fingering, which (for the first time) she had not let shake her confidence. And what else? Oh, yes! Her mother was so proud of her that night she celebrated by taking Nikki out for dinner-and letting her have her very first drink. They'd gone to the Players, where her mom was a member. The club sat only a few doors from their place but carried a grand history and specialness to Nikki. Her mother asked the bartender to go in back and unlock her private wine locker for a special bottle. When he uncorked it and left, Cynthia drank down the water from Nikki's gla.s.s then poured her daughter some of the celebration wine. Her mom only allowed the sixteen-year-old a half gla.s.s. To Nikki, it was br.i.m.m.i.n.g.

Heat checked her watch and stood. The new warmth that flowed through her came from something more than revelation, more than closure. She felt a connection.

Nikki put on her coat and stepped out.

The bartender's hair had gone white over the years but he still remembered Miss Heat, same as he recalled everyone who ever had been a member or honored guest at the Players. If George had been working the Grill Room when Samuel Clemens knocked cue b.a.l.l.s around the billiard table that still lived there, he would have memorized every shot, quip, and bawdy curse from Mr. Twain.

He got his keys off the hook above the bar sink, and as he led Nikki to the back, he said, "I still see your dad come in from time to time. Although not so much since..." George's brow fell. He left it there.

In the back of the room, past cases of hard liquor and house wines, built-in cabinets filled a wall. "Here we go," said George, "the private stock." Each cupboard, the size of a small gym locker, was marked by an oval bra.s.s plaque etched with the member's name. Nikki recognized a lot of them; most belonged to famous actors, but a few to composers, journalists, and novelists. They weren't arranged alphabetically, but the barkeeper knew where each stash resided, by heart. He fit the key into the door of the locker labeled "Cynthia Heat" and stepped back. Discreet to a fault, George smiled and said, "I'll leave you to do the honors," then melted away to the Grill Room.

Heat opened the door and found no wine. All the locker housed was a solitary bottle of beer: Durdles' Finest Pale Ale. A banner on the label read, "Now crafted in America at Brewery Boz, South Street Seaport." Nikki lifted the bottle and saw her name on the envelope it had been resting on.

She ran the pad of her forefinger over her mother's handwriting and opened the envelope flap, which Cynthia Heat had left folded but not sealed.

The note to Nikki was short. She absorbed it with surprise, at what it said and at the unexpected sense of closure she'd always believed could never come. The words under the signature at the end of the note made her eyes cloud with tears: "Always remember Mom loves you."

She left the beer, took the note, and departed with one fewer loose end, and then some.

Nikki's quad protested as she stretched on the mat at her gym early the next morning. The soreness from the physical ordeal of the past weeks, coupled with skipping workouts and sleep, made her feel like an out-of-shape slug. Heat smiled through her grimace, thankful she belonged to the only gym in Manhattan without mirrors.

When Bart Callan came in, he was grinning, too. "You weren't kidding, Heat. This facility is bare-bones. I expect to see Rocky Balboa working a side of beef."

"I like it this way. No frou-frou, no posers. It's come to work, or stay out."

"Is that why we have it all to ourselves?" He dropped his gym bag in a corner then stripped off his sweats down to his basketball shorts and a Homeland T-shirt with the sleeves hacked off, revealing seriously ripped upper arms. She wondered if he had altered his tee just for her.

Heat and Callan double fist-b.u.mped in the center of the mat to signal readiness. Nikki shifted her weight back and forth on the b.a.l.l.s of her feet to get a read of him, and in an instant, she got her a.s.sessment. He made a feint left and a lunge right, grabbing her waist and sending her to the mat. "Finally," he said. "Contact."

"Man." She got up and said, "Rusty."

This time she went for him. As she came forward, he dropped to a knee and flipped her over his back, and she came down with a thud on the mat. "Remember, you called me," he said. "You sure you're up for this?"

"We'll see. I didn't sleep much last night."

"The arraignment?" He waved the air dismissively. "Don't sweat that."

They circled each other, throwing decoys and fakes, n.o.body committing yet. "I'm fine with the arraignment. I was awake because I finally broke a coded message my mom left me." She threw a low shoulder, straight to his waist. He didn't react in time and he went down. This time, she helped him to his feet. "She definitely busted Carey Maggs."

"A little late now that we closed the case, but congrats."

Heat shook her arms to keep limber. "Bart, when I asked you to check Maggs out, didn't you send me an e-mail clearing him?" He must have thought she had her guard down. He suddenly dropped to his seat and made a leg sweep toward the backs of her knees. But Nikki jumped his move like a double-Dutch, landed on her feet, then danced in place, letting him haul himself up this time.