Jason Walsh was planning - no, he was determined - to sleep in that day. Allison wasn't off shift until after noon and he figured he needed to rest up before she showed up to ravish him. He'd even taken his land line off the hook and set his cell to ring only if Allison or the precinct called.

Sure enough, Murphy's Law was in effect - there went the phone. Walsh growled loudly into his pillow and then rolled to grab the offending device. The number showed it was the precinct calling.

"Walsh. Make it good."

"Shraeger's missing."

Tony Stark stepped out of the elevator at the 12th Precinct and glanced quickly around. When he caught sight of the man slumped in a chair next to someone's desk he made a beeline for him.

"Castle," said Stark. "What the hell is going on?"

Rick Castle looked up at him with weary eyes and a set jaw and said, "Hey, Tony. Alexis is missing."

"God, I'm sorry to hear that," Stark said. "I am, really, but do you know a detective named Beckett? I was told to meet her here, that she might know something about - "

"Virginia Potts," said a woman's voice behind him. Stark spun around to behold a tall brunette with coffee in one hand and a file in the other. The badge clipped to her belt designated her a member of New York's finest.

"Detective Beckett?"

"Mr. Stark," she said, setting down the coffee and shaking his hand. "Come on, Castle, let's take this party into the lounge."

She led the way into a small room with comfortable chairs and a large table; Castle dropped into an armchair and Stark perched on one arm of the sofa.

"I just got a call from Sergeant Brown over at the Second," she said. "He's sending over the missing cop's partner, says we're welcome to pick his brain."

"Missing cop?" Stark frowned. "What does this have to do with Pepper?" At Beckett's blank look, he added, "Pepper Potts. Nobody calls her Virginia - well, nobody who knows her, anyway - She's the CEO of Stark Industries, she's my - well - "

"Girlfriend," came a new voice through the doorway. An unassuming man in a gray suit walked in and went straight to Beckett. "Jason Walsh, Second Squad."

"Kate Beckett." She shook his hand. "This is Rick Castle; his daughter is missing, and Tony Stark, whose, um - "

"Girlfriend is also missing," said Stark. "Nice to meet you, everybody, but what the hell is going on?"

"Detective Beckett," said the newcomer, "your department doesn't handle missing persons as a rule, does it?"

"You don't have to be delicate about it," said Castle. "It's a homicide division."

"Wait, what?" Stark stared at Castle. "Okay, somebody had better give me a clear, concise explanation as to why we're all talking to a homicide detective about people we hope are still alive."

"My partner, Casey Shraeger, was abducted from a club last night," said Walsh.

"My daughter disappeared from the Palace when she went to the ladies' room," said Castle.

"Pepper went AWOL from a gig at Rockefeller Center," said Stark.

"And they all have one thing in common," said Beckett. She laid three photographs on the table; one was a stylish woman in a gray suit, one a serious woman with an NYPD badge, and the last was apparently a school picture of a young lady with brilliant blue eyes and a dimple. "Three guesses."

"All redheads," said Walsh. "Of various shades."

"Wow," said Castle, standing to get a good look. "No kidding. All natural, I'm guessing?"

"How would you know that?" asked Beckett suspiciously.

Castle flashed her a smile.

"Alexis went to see that revival of Annie with my mother, who reports that they went to the ladies' at the same time. She left the room first and Alexis never came out."

"So?" Walsh inquired.

"So, my mother has red hair as well, and she'd be easier to capture than a teenager with her wits about her and a mean right hook," said Castle. "But my mother's hair color is, alas, less than authentic. Far less."

Beckett suppressed a smile and said, "To the best of your knowledge, Mr. Stark and Detective Walsh, is Castle's assumption correct?"

"As far as I know," Walsh shrugged.

"Absolutely," said Stark. "Which doesn't answer my question."

"We're investigating Alexis' disappearance because she and Castle are like family to us," said Beckett evenly. "When I started following up on clues we discovered two other women who have been reported missing in the last week, both in a ten-block radius, both while away from home, and both redheads."

"So when Shraeger and Ms. Potts were reported, you noticed the connection," said Walsh.

"Right. We have not, however, found any bodies of women with red hair in the past week, so I'm hoping this pattern has more to do with someone's fetish than some intent to kill."

"And that's usually my favorite word," Castle was heard to mutter.

"Which word - kill?" said Walsh, frowning.

"No, 'fetish'. Inside joke, never mind."

"It gives me an idea, though," said Stark. He stopped pacing and stared at the three photos. "Did these women have anything else in common besides their hair color?"

"Alexis and Shraeger are unattached," said Beckett.

"One of the other women is married, but estranged," Beckett went on. "The other is a model whose personal relationships are, shall we say, constantly in motion."

"No obvious correlation in terms of age," said Walsh, looking over the board. "Economic status?"

"Castle and I are probably the best sources for ransom requests," Stark mused. "Liquid assets and all."

"Do we have any financials on the other women?" asked Castle.

"The thing is, we haven't had any ransom demands," said Beckett, "so we haven't gone looking for a money motive yet."

"It might not matter, though," said Stark. "I think I can get someone to volunteer as bait. Someone with actual red hair who is not only lovely to look at, but deadly to hold."

Walsh was looking at him like he wanted to measure him for a straitjacket. Beckett looked like she was waiting for the other shoe to fall, and Castle -

"Are you kidding me?" he blurted out. "She's a true...?"

"I've seen her in varying states of undress," Stark told him. "Usually during or after a mission. And I can hereby attest that the carpet matches the drapes."

"Shut the front door." Castle looked impressed. "And she let you live?"

"As a favor to Pepper."

"What are you talking about?" Beckett asked, confused.

Castle and Stark turned to her as one and said, "The Black Widow."

Stark valiantly volunteered to enlist the assassin in question; when he ended his phone call he breathed a great sigh of relief.

"She says she'll do it, but on her own terms."

"What's that supposed to mean?" said Beckett.

"We can't pursue anything without knowing all the angles," said Walsh. "She needs to work with us."

"Sorry, detectives," said Stark, "but there's only a lucky handful of people she'll condescend to collaborate with, and none of them work for the NYPD."

"What about you?" Castle asked.

"Sadly, I am not included in that number, either," Stark reported, but he didn't sound at all disappointed. "If our fixated kidnapper can be lured, she can lure him. She'll give one of us a heads up once she gets him on the hook."

"What do we do now?" Castle was pacing the entire perimeter of the bullpen, growling and muttering. "We waited, we did it her way, and now she's vanished as well. We're no better off than we were twelve hours ago."

"No ransom demand, no proof of life recording," said Beckett's colleague Ryan from his desk. "No evidence of abduction at her last known location. If she went, it was without a fight."

"Not possible," said Stark tightly. He was staring at the white board covered with notes and images. "She never does anything without a fight. Ask Barton, he - "

He straightened suddenly. "Ask Barton. That's it."

"Barton who?" said Walsh.

"Clint Barton. You know him as Hawkeye, he's been her partner, in more ways than one, rumor has it - they're the deadliest non-superhero humans I know. If Natasha had a plan, and she didn't tell us about it, she must have told Barton."

He was hitting the speed dial on his phone as he spoke; after a few seconds listening to it, he grimaced and stuffed it back in his pocket.

"Straight to voicemail. He was in town this morning, but he might have been sent on a mission somewhere else since then."

"You said they all disappeared from a ten-block area near Rock Center," said Walsh, coming over to look at the map posted on the board. "These are the last known positions of the five abductees who fit our profile. Where was Agent Romanov last seen?"

"Witnesses put her at the cast entrance to Radio City Music Hall around six," said Ryan. "She told somebody she was there for an audition, and when the guy at the door said she was mistaken, that there were no auditions today, she just batted her eyelashes at him and went on her way. This from one of the performers who went inside right after."

Castle was muttering to himself. "Radio City Music Hall. Rockefeller Center. The Palace. All landmarks. All redheads..."

"And what the hell for?" said Beckett.

Silence reigned for a few minutes - then Castle suddenly straightened in his chair, so abruptly that it almost fell over.

"Prometheus," he snapped. "I know where they're being held. I don't know why, but where - "

The others watched as the writer leaned in and drew a circle around the Lower Plaza.

"That iconic sculpture that looms over the ice rink," he prompted. "Prometheus - the god who brought fire to the mortal realm."

"Fire," Stark echoed. "Like their hair - "

"The concourse under the plaza." Beckett scrambled for the floor plans scattered over her desk. "There's a large maintenance room right - here, not for the vendors but for the ice rink."

"So, off the beaten path, probably out of sight of the general public," Walsh put in, looking over her shoulder.

"I'll call the facility management, see if anyone's used it lately," said Ryan.

"You and me?" Beckett said to Walsh, who nodded briskly.

"What about - " That was as far as Stark got before Beckett shook her head.

"Not you, and not Castle," she said firmly. "I've seen both of you in action, but with all due respect, I want to keep our numbers small and professional, if you know what I mean."

"Sure," said Stark. "I get it."

Castle shot him a surprised look but said nothing; Ryan had disappeared and Beckett and Walsh swept out before he spoke up.

"Stark," he said. "You're not sitting still for this, are you?"

"Not any more than you," Stark told him. "Come on, let's go ice skating."

He clapped Castle on the shoulder; they both grinned and headed for the elevator.

Beckett and Walsh had alerted the plaza manager to their presence and purpose and were walking along the concourse as if window shopping.

"About another twenty yards, on the left," Walsh said under his breath. "Your backup?"

"Esposito and Ryan are in position," Beckett replied. "There's no back exit from the room itself, so if he's in there he'll have to go through us to escape."

"And we still don't know who or why." Walsh shook his head.

"Or how many," said Beckett. They approached the door in question and Beckett leaned to peer through the crack where it adjoined the jamb.

"Shut up solid, no light at all," she reported quietly. She laid her ear to the crack as well and said, "No sound either. Ready?"

"Right," said Walsh, drawing his gun but keeping it close, out of sight of anyone who might wander their way. "Go."

Beckett swiped the security card they'd been given and nothing happened. Grimacing, she swiped it again and this time was able to shift the door open about an inch. Keeping clear of the opening, she knelt down and called out, "Hello? Anyone in there?"

Not a sound. She eased the door open further, standing to step quickly into the room, which was dark and silent. Walsh was behind her, shutting the door but not all the way. Wordlessly they separated, creeping along opposite walls, looking for any signs of disturbance.

"Footprints in the dust," said Walsh. Beckett followed his gesture of direction as her eyes adjusted to the dimness, seeing shoe prints in a waffle pattern, not much bigger than her own. One set, one walker.

There was equipment stacked nearly ceiling high, covering two of the four walls; Beckett frowned when she spotted an ice resurfacer, not very large, parked against a wall and surrounded by crates. She stepped closer and felt a draft.

"There," she whispered to Walsh. "Behind."

He came over to take a look and nodded.

"Can you drive it?" Beckett asked and he nodded again. Holstering his gun, he climbed up in the seat of the machine and hunted around for controls. Beckett took up a position close to the wall to cover what she suspected was an opening behind the Zamboni.

"Here we go," said Walsh. He started the engine and almost immediately put it into gear, letting it roll about two feet and revealing a hole low in the wall. It was about three feet by three and curtained with a tarp on both sides.

Walsh cut the engine and hopped off the Zamboni, joining Kate at the opening, but they never had to fire. The long silence had been broken by the sound of several female voices, some shouting for help, others barking what sounded like commands.

"NYPD!" shouted Beckett. "Coming in!"

Walsh ripped the tarp down and both of them went through the opening, ducking down and straightening on the other side, shoving boxes out of their way.

Beckett was expecting to find several hostages in the small, poorly-lit room - but there were only two, facing each other, but looking at the ceiling. As Walsh and Beckett burst in, one of those two spun into a defensive posture, but the other one said, "Stand down, that's my partner!"

Casey Shraeger, of the Second Precinct, grinned over at Walsh as her companion froze.

"You must be Detective Shraeger," said Beckett. "Kate Beckett, Twelfth Precinct. The hostages?"

"Evacuated through the ventilation system," said the woman standing next to Shraeger. She was petite with short, dark red hair, almost the same hue as Shraeger's. "Agent Romanov."

"Agent of what?" said Walsh suspiciously, but Shraeger shook her head.

"Later," she said. "Let's get out of here. Not that way," she added as Walsh turned toward the hole they'd opened. "Through the vents."

"Why, and to where?" Beckett asked warily, looking up at the opening in the ceiling.

"My partner is about to set an ambush in the room you were just in," said Romanov. "He's armed and ready to take out the hostile - there's only one, and he is armed also. If we go that way, we'll only get in Barton's line of fire."

"Okay," Walsh said, looking at his partner for confirmation. "So, where did the hostages go?"

"Over here," called Castle from the opposite side of the ice. Stark skated over and bent down to look where the other man was pointing.

"Yep, looks big enough," said Stark. "As long as none of the ladies are too plus-sized."

"Listen!"

The faint sound of a stifled sneeze emerged from the grate they stood beside.

"That's Pepper, or I'll eat my helmet." Stark rubbed his hands together, then tapped his earpiece. "JARVIS, nearest place for hot food in a hurry?"

While Stark planned the recovery mission, Castle got out his penknife and worked on the screws holding the grate in place. To his surprise, they were fairly loose and the grate came free just as a shuffling sound from within got closer.

Castle knelt down and peered into the opening and was rewarded with the sight of red hair, dusty and disheveled, on a familiar head. He gave a low whistle and his daughter's head came up; when she saw him she broke into a huge grin and shuffled faster.

She was crawling along on her elbows, about twenty feet from the opening where Castle and Stark waited, and they could see the dim forms of other women behind her. From the vent opening to the surface of the ice was a drop of only three feet or so; Castle steadied Alexis as she slithered out, staggering, onto the ice. There were seven women in all, with Pepper bringing up the rear in a now-grey suit and no shoes.

By now the escape had attracted spectators - and law enforcement. Beckett's colleagues from the Twelfth showed up and collected the hostages, leading them into the concourse to warm up and debrief. Alexis and Pepper were reluctant to go, but their numbing feet convinced them otherwise.

"I just hope we haven't scared the bastard off," said Pepper. Stark stared at her as she put her arm around Alexis and followed the rest of the group.

"She never uses language," he muttered. "That's my department."

"What did she say about Beckett and Walsh? And did they find Agent Romanov?"

"From what Pepper told me in the space of thirty seconds, Romanov is supposed to be in the vents, along with Barton - don't ask - and Walsh and Beckett are lying in wait for the guy with the Titian fetish, who was due to bring food for his guests some time this afternoon."

There was a sudden burst of noise from the vent opening, both voices and metal; Castle said, "Right on cue. I hate waiting."

The two men listened to incomprehensible sounds for about five minutes; then yet another woman appeared, climbing out of the vent.

"Agent Romanov, I presume?" said Castle once she was standing.

She gave him a wary look, but Stark chimed in with, "Richard Castle. His daughter was one of the hostages - he works with the NYPD - more on that later. Where's the rest of the posse?"

"Walsh, Shraeger, and Beckett were hidden around the room," she reported. "I was in the back room in case the kidnapper tried to retreat into it. Apparently the guy was in the middle of the room when the cops popped up and challenged him, he tried to fire, and then - "

She chuckled, a sound Stark had never heard from her, then went on. "Then Clint dropped out of the vent, right on the guy, who went down, and when he climbed off the guy was disarmed and freaking out. Said he must be hallucinating."

"Why?" said Castle as they headed for the concourse.

"Wait till you meet Barton," said Stark.

Sure enough, Romanov's partner was an eerily near-perfect copy of Jason Walsh; he stood with the three detectives giving a quick debrief to Ryan and Esposito, and the suspect flinched every time he looked at either Walsh or Barton.

The freed hostages were warming up in a corner of one of the larger coffeeshops; Stark appeared to be persuading the staff to accommodate their group, probably for a more than generous gratuity, thought Castle.

The suspect was led away and the redheads were giving their statements to a collection of officers; Stark came up to stand with Castle, looking relieved and smug at the same time.

"Quite the collection, aren't they?"

The women ranged widely in apparent age, style, and dimensions, but their hair ran the gamut from strawberry blonde to Alexis' brilliant tangerine.

"Beautiful," Castle agreed, just as Beckett came over.

"Are you ready for this? The guy was 'collecting' redheads in order to find a perfect match for the color of Lucille Ball's hair," she told them. "He said it was 'a color that comes along once in a generation.' We haven't found out yet what he was going to do once he found one."

Stark laughed and Castle smirked.

"He should have saved himself the trouble," said a sardonic voice from behind them.

"Mother!" Castle turned to the lady who'd spoken, who appeared to be of mature years, vaguely familiar, and definitely red-haired. "Tony Stark, Martha Rodgers."

"What do you mean, he should have saved some trouble?" asked Stark, shaking the lady's hand.

She grinned.

"Lucy's hair color was one of a kind, all right. She and her hairdresser concocted a wash out of regular hair dye and henna and kept it locked in a safe, and no one ever knew the exact mix. He could never hope to duplicate it, let alone find it in nature."

"He'll be crushed," said Castle. "Only her hairdresser knew for sure."