"Beer?" offered Castle with a strained smile when he opened the door to the loft and ushered Ryan and Esposito in. "Or do you want to skip straight to the hard stuff?"

It was barely past noon, so the detectives merely scoffed at the writer's weak attempt at a joke. Under other circumstances they might have laughed and teased him back, but this was no ordinary situation.

Beckett was ensconced on the couch with a blanket and a glass of water. As the others walked toward the living-room area, she moved as if to get up and greet them, but all three men frowned and waved her back down. She relented and sank into the cushions, much to the relief of her aching back.

All four of their faces were pinched tight with tension, and Beckett wasted no time in cutting right to the point. "Are we sure it was her?"

"Yeah," Espo confirmed, following her lead, speaking bluntly. "No doubt about it, Captain. She's back."

"Or she never left," Ryan said, which didn't make any of them feel any better.

As the men took seats on the couch and end chairs, they all exchanged matching looks of trepidation. Beckett knew that if they allowed themselves to fall fully into the grip of the anxieties that were plaguing them, they'd never get anywhere. So she took refuge, as always, in the case. Focusing on the work would get them through.

"Okay. Let's review," she said, forcing an authoritative tone, clenching her hands in her lap to keep them from trembling. "Everything we know about her from the previous cases."

"Right." Esposito sat up straighter, nodding. "I asked Marisa to pull the files so we can go over them, but I don't think any of us have forgotten the particulars."

"Megan Bailey's sister died when she was a kid," Ryan said as if reciting a lesson from memory. "Unremarkable family life otherwise, as far as we know. She finished high school but never went to college. Obsessed with phobias."

"She murdered, what, five people?" Esposito added, picking up the thread. "All of them killed in ways that reflected their own worst fears. She worked at the psychiatric office, which gave her access to patient records so she could find out what her victims were scared of."

"And she was obsessed with you, Beckett," Ryan finished, looking at the floor, as if he couldn't bear to meet his boss's eyes - or those of her husband.

"Right." Beckett swallowed carefully, again forcing down the worries that kept threatening to rise up and choke her. "We still have some holes in her background, though. I need you guys to dig in again - find out everything we missed last time. Details of her sister's death, where the parents are, her relationship with them. Every job she's ever had, hobbies, associates."

"We need to know where her fascination with phobias came from," Castle added. "That seems like an important detail that might help us figure out how to stop her."

"Yeah," Ryan said, as they all nodded agreement. "And of course we're going to work on figuring out where she's been hiding all this time. It seems that she may have been using Susan Murphy's identity for a while now, so Vikram is tracing Susan's financials to see if we can find anything in that."

"We've got unis searching the hospital floor by floor," Esposito added, "although she's probably long gone by now."

"And we've got an APB out," Beckett said. "I also suggested that they increase security on the maternity ward, in case she comes back to try to kidnap another baby." She looked from one man to the next, meeting each of their eyes in turn. "We've got this, guys. We're going to get her this time."

Castle opened his mouth as if to say something, but then changed his mind and closed it again. Beckett cocked her head at him, asking the question with her eyes, but he shook his head minutely, so she let it drop - for now.

"You guys better get back to the precinct," she said to the detectives, and they both nodded and got to their feet.

"We'll keep you posted," Esposito promised.

"Thanks."

As Castle walked the two detectives to the door, he shot her a cautious look and dropped his voice to a hushed tone, so Beckett took out her phone and pretended to be engrossed in an email, all the while straining to make out what the three men were saying.

"I'd come with you guys, but-" Castle began, but the others shook their heads, Esposito putting up a hand to forestall him.

"Dude, don't be crazy. You gotta stay here with Beckett."

"Yeah," Ryan chimed in. "Keep her safe."

"You better believe it," Castle said grimly, and then he was closing the door behind the others, turning to rejoin Beckett in the living room.

"Hey," she murmured, dropping her phone onto the couch and reaching her hand out to him. He lowered himself carefully next to her, taking her hand and clasping it between both of his, resting on his knee.

"Kate," he said before she could speak, his eyes fierce. "I think you should go away."

"What do you mean?" she asked, startled. "Go where?"

"Anywhere," he said, gesturing jerkily with one hand. "The Hamptons, your dad's cabin upstate, Siberia. Somewhere far away from- from here. Somewhere you'll be safe."

"Oh, Castle..." The baby wriggled within her, and Kate thought whimsically that Lily was reacting to her father's suggestion, the same way she was. Of course he just wanted them to be safe, but there was no way she was going to leave town - not at this point in her pregnancy.

As she rubbed her other hand gently over the swell of her belly, Beckett thought about Megan Bailey, and realized slowly that she simply wasn't willing to be scared any more. The serial killer might be clever and ruthless, but how could she compare to what Beckett had - family, friends, a team of experienced detectives at her back and by her side?

"No," she said firmly, stroking her thumb along Castle's knuckles. "We're not running away; we're not going to hide. I'm staying right here, and we're going to catch Bailey and have our baby and be happy."

"Kate, come on," Castle said fretfully. "You know it's not a coincidence that she happened to take the identity of a nurse who works at our obstetrician's office, who's connected with the hospital where we're going to have our baby."

"No, it's not," Beckett agreed with a nod. "We know that she's obsessed with us for some reason, but listen." She squeezed her husband's hand, waiting for him to meet her eyes before she continued. "Think, babe. The last two times we encountered her, those murders were carefully planned out and executed. She put months of preparation into them, and staged them to get our attention."

Some of the tension flowed out of her shoulders when she saw Castle pause, the anguish fading from his expression as his logical brain kicked back in. "Oh," he said slowly, picking up her thought. "But this incident today wasn't like that."

"Exactly," she nodded, smiling with relief. It was so good to be doing this again - thinking through the details of a case - applying logic, detective work, and their collective years of experience. She felt her spine straightening as she laid out her next point. "Whatever she was trying to do this morning, it wasn't planned. With a nurse's badge she could have kidnapped that baby quietly at any time. But making a public scene like that? That's not her M.O."

"She snapped," Castle concluded, his eyebrows drawing downward thoughtfully. "If she is planning something, there's no way that was part of it."

"She's losing her grip, getting sloppy," Beckett continued. "And that means we have the upper hand. She's going to slip up again, and we'll be there."

Castle's expression darkened again. "But Kate, coming unhinged also means she's more dangerous than ever." He shifted closer, reaching for her other hand, holding onto both of her hands like a lifeline. His eyes were stormy as he pleaded with her. "You can't put yourself into more danger, not now. Not when we're getting so close to Lily's arrival."

"I won't," she assured him, pouring as much sincerity and confidence as she could summon up into her voice and face. "Babe, I promise you. I'm not going to let anything happen to our baby, or myself. But remember what else we know about Bailey - she thrives on our fear. She wants us to be scared. So if we give in to it..."

"She wins," Castle finished, heaving a sigh.

"Right."

Kate disengaged one of her hands from his grip and slid it up his arm, squeezing his shoulder, then letting her palm rest soothingly on the back of his neck. He closed his eyes briefly, leaning into her touch.

"I know," he said, a near-whisper directed toward the floor. "I know you're right, but it's just easier said than done, Beckett." He lifted his head to meet her eyes again. "How can I not be terrified, with you and Lily at stake?"

"Hey." With difficulty, Kate scooted herself a little closer, pulling Castle in for a hug. "I'm not saying that I don't feel the same, Rick. I'm scared too, but I'm not going to let it rule me. Not this time."

He let out another sigh, his breath gusting unsteadily across her neck. His arms encircled her torso and squeezed gently.

"Okay," he said into her skin, his tone straining to sound confident. "We can do this. We're going to get her."

"Yeah, we are."

The baby moved again then, wriggling urgently against the press of Castle's elbow. They both chuckled lightly, wiping at their eyes as he pulled back.

"Sorry, peanut, didn't mean to squish you."

"I think she needs some more water," Kate said, looking to the side table where she had put her glass down. But it was empty. "Oh, babe, could you-"

"Of course." They exchanged tender smiles, and he kissed her softly on the cheek before standing up and reaching for the glass.

As Castle headed to the kitchen to refill the glass, a sudden deep twinge seized Kate, a strong clenching pain throughout her belly. The intensity of it almost drew a gasp from her, but she bit her lip and held it back.

It wasn't the first time today that she'd had a spasm like this - similar to the Braxton-Hicks contractions she'd been having for months now, but stronger, sharper. They had started a few hours ago, just after she and Castle had left Dr. Kowalewski's office, but she hadn't thought much of it.

Was it possible that these weren't Braxton-Hicks after all? Could they be the real thing?

She chewed on her lower lip and surreptitiously checked her watch. She would keep an eye on it, she told herself, and see how far apart the pains were coming. There was no need to mention this to Castle yet. He was worried enough already.

Ryan sat at his desk in the precinct, frowning to himself as he re-read the email he had just composed.

Hi again, it read. Thanks very much for answering my additional questions about the job. I'm honored to be considered for this. I'm sure you understand, leaving the homicide team here at the 12th is a really big decision for me, so I hope it's still okay if I take a little more time to think it through, as we discussed. I'll get back to you very soon. Sincerely, Kevin Ryan.

As he sat there staring at the words on the screen, his cell phone pinged with a text from Jenny. Did you send that email yet? it read. Ryan couldn't help smiling. Somehow his wife had a way of sensing when he was being indecisive.

He clicked Send on the email, and texted Yep, sent it just now to Jenny.

Then he mentally put all of that aside and switched the computer view back to the warrant request he had been working on.

"Anything?" his partner asked, emerging from Beckett's office.

Ryan looked up from his computer and shook his head. "Nope. You?"

"Nothing useful," Esposito replied, his features twisted with frustration. "Bailey escaped into the stairwell, where there are no cameras, and she could have exited the stairwell in any one of a dozen places without being seen. Including the parking garage. So we don't even know if she's still in the hospital or not."

"I found the name of the therapist who did her grief counseling after her sister's death," Ryan said, returning his eyes to the computer screen. "I'm putting in a warrant for those records."

"You sent unis over to her apartment, right?"

"Yeah, but they struck out. The landlord rented it to someone else a couple months ago, and the new tenants haven't seen or heard anything."

"I think I have something!" came a voice from across the room, and both detectives looked up as Vikram popped out of his tech room, a slip of paper in his hand.

"Let's hear it," Esposito said, his tone reflecting the same sense of urgency that Ryan felt. As the tech analyst approached, Ryan saw that Vikram, too, felt the same way. They had to solve this, and fast. Their captain - their friend - was depending on them.

"Okay," Vikram said, speaking hastily in his rush to tell them what he had found. "I figured since Bailey was using Susan Murphy's identity at the hospital, it was possible that she'd used it in other places too. So I ran a credit-card search and found that Susan - or at least someone using her name - applied for a credit card a few months ago. Using a billing address that doesn't match her home address."

"What? That's huge," Ryan exclaimed, hitting the Submit button on his computer and leaping to his feet. "What's the address?"

"Here," Vikram said, handing over the paper with the address scribbled on it.

"Let's go," Esposito said, but just then his cell phone rang. He pulled it out as he and Ryan strode toward the elevator. "Esposito."

Ryan signaled to a few uniforms to accompany them, listening to his partner mutter "Okay" and "Yeah" as they waited for the elevator to arrive. "Okay, be there soon," he concluded, and hung up.

"Whatcha got?" Ryan asked. The elevator doors opened and the two detectives and three uniforms piled in.

"That was Dr. Sutherland at the hospital," Esposito said. "Says they found something while searching the maternity floor, wants us to come see."

"What is it?"

"A storage room that had been closed off for several weeks now, and when they tried to open it, they found that the locks had been changed," Espo explained, frowning. "The hospital janitors couldn't get it open, so they called a locksmith. He's on his way." Espo pushed his phone back into his pocket. "I'll go over there and see what's in the storage room. You go to the apartment. Check in when you get there."

"Right." The elevator doors opened on the ground floor, and they all rushed out, heading off in different directions.

"Are you sure you don't want any more spaghetti?"

"Really, babe, I'm stuffed," Kate said with a smile, pushing her plate away. "There's not much room in my stomach any more, you know."

"Right, right." Castle nodded and tried to hold his tongue as he cleared the plate and refilled Beckett's water glass. He knew he was fussing over her more than she liked, and any minute now she was likely to snap at him if he didn't tone it down.

He couldn't help himself, though. The closer they got to their baby's arrival, the more excited he felt; even the reappearance of Megan Bailey couldn't entirely dampen his enthusiasm. And pampering Kate was the closest he could get to spoiling his new daughter, for now.

"Drink some more water at least," he urged, and Kate picked up the glass, rolling her eyes mildly.

As Castle put the leftovers from their lunch into a container for later, his iPad chimed softly, the screen displaying an alert from the new security system he'd had installed after their last encounter with the serial killer. It was programmed to notify him whenever the elevator stopped at their floor.

He frowned down at the display, wondering who it could be. Their neighbors in the apartment across the hall kept a very consistent schedule, and didn't usually come home this early in the afternoon. "Expecting someone?" he asked, glancing over at his wife, who raised her eyebrows and shook her head.

Pursing his lips, Castle swiped the iPad on and opened the security app, which showed him a live feed from the surveillance camera in the outer corridor. He turned the tablet sideways so that Kate could see it too.

They were both surprised to see a familiar form walking down the hallway from the elevator and approaching their door.

"LT?" Kate exclaimed. "What's he doing?"

On the screen, they could see that the officer was wearing jeans and a t-shirt rather than his uniform; a baseball cap was on his head instead of the uniform hat. But his gun was in its usual place on his hip. He made no attempt to knock or ring their doorbell, merely stopped next to their door and assumed a parade-rest stance: feet apart, thumbs hooked in the belt-loops of his jeans.

Curious, Castle came out from behind the kitchen island and moved across the room to open the door. Kate slid off her stool and followed him.

"What's going on, LT?" Castle asked as he opened the door.

"Hey, Castle," the officer said easily, giving him a friendly nod. "Heading out?"

"I, uh, no," the writer stammered, blinking. It occurred to him that he'd never seen the other man out of uniform before.

"LT, what are you doing here?" Kate asked. "Your shift ended an hour ago."

Castle couldn't help smiling to himself. Of course his wife still knew the 12th Precinct's duty roster by heart, even while she was on maternity leave.

"Protective detail," the officer explained, giving Kate a respectful nod.

"What?" Beckett's forehead creased. "By whose orders?"

"No orders, Captain," LT said laconically. "Me and the other uniforms put together a schedule on our own."

"A schedule for standing guard outside our door?" Castle clarified, and LT nodded confirmation.

"Yep." Seeing the surprise on their faces, he added, "Not letting that serial killer get past us again. She tries anything, we'll be ready."

Castle looked at his wife, who was smiling slightly. "Thanks, LT," she said softly. "That's really sweet of you - all of you."

"No problem, Cap," LT replied, ducking his head, apparently uncomfortable with Beckett's display of emotion. "Don't mind me, I'll just be out here."

"Well, uh, can I get you anything? Coffee?" Castle offered, but LT shook his head.

"Thanks, Castle, I'm good."

"Okay..." Castle closed the door and turned to his wife, who was still smiling.

"Can you believe that?" she asked, her voice low and warm with pride.

"Yeah, I can," Castle replied honestly, enjoying the way her eyes widened at the statement. He reached out and squeezed her shoulder. "That's the kind of loyalty you inspire, Beckett. They're lucky to have a captain like you, and they all know it."

"Stop it," Kate said half-heartedly, turning her face away and blinking hard. "Stupid hormones," he heard her grumble under her breath, and he chuckled softly.

"Sorry," he said, letting his grin show that he wasn't really sorry at all.

Kate stepped forward and put her arms around his waist, lifting her face up toward him. He took the hint and bent down to kiss her lightly, his hands falling easily onto her hips.

"Thank you," she whispered against his lips, and then pulled away, her hand going to her lower back, a grimace crossing her face.

"You okay?" he asked, concerned, but she nodded and mustered a smile.

"Fine, babe. Don't fuss," she chided. "I'm just going to go lie down for a few minutes. Don't let me fall asleep."

"Kate, you know perfectly well that you're going to fall asleep, and I'm not waking you up," he scoffed. "You need all the rest you can get right now."

"I mean it," she said, flashing her stern glare at him. "We need to stay on top of this investigation, Castle. Don't let me sleep the afternoon away."

"I'll wake you if there's anything really important," he said, and they both knew that she knew it was an evasion, but she let it drop.

Castle stood for a moment watching Kate make her slow way toward the bedroom, and then he returned to the kitchen to finish cleaning up their lunch.

"NYPD! Open up!" called Ryan, pounding his fist on the door of the apartment that was listed as the billing address for Susan Murphy's credit card. The three uniformed officers and the landlord stood by, tense, listening with Ryan for any sounds of movement from within.

The landlord had nodded when Ryan showed him a photo of Megan Bailey. He confirmed that the woman in the picture was probably his tenant, although she had been wearing dark sunglasses and a low-slung hat the one time he met her face-to-face.

After a minute of silence ticked by, Ryan banged on the door again. "NYPD! We're coming in," he yelled. He waited another long moment, then turned to look at the landlord. The man stepped forward, master key in hand, and unlocked the door.

Ryan's shoulders were tense with apprehension, his fingers tight around the grip of his gun. He eased into the apartment with the uniformed officers close behind. It was dim, the interior lit only by daylight coming through the cracks between the window coverings, until the landlord flipped the switch by the entrance and the lights came on.

They swept quickly through the apartment, tense voices calling out "Clear!" from each room as they checked it. There seemed to be no one here.

Ryan was opening the coat closet just in case when he heard an officer call from the rear of the apartment. "Uh, Detective? You should probably see this."

As he made his way down the short hallway, his phone rang, the screen lighting up with Castle's picture. "Hey, Castle."

"Hey, Ryan. Vikram filled me in," the writer said. "Are you at the apartment now?"

"Yeah, she's not here, but the landlord identified her." Following the officer who had summoned him, Ryan stepped through the door of the room at the end of the hall, and stopped short. "Whoa."

"What?" When he didn't immediately answer, Castle's voice came through the speaker again, tight with alarm. "Kevin?"

"Um, Castle, hang on, I'm gonna FaceTime you," Ryan said. He didn't wait for a reply before ending the call and tapping his thumb on the screen to initiate a FaceTime request. His eyes roamed the room, a shiver prickling his spine as he waited for the call to connect.

"What's going on?" Castle asked when his face appeared on the screen. "What is that?" He sucked in a sharp breath as Ryan held up the phone and panned it slowly from one side to the other, letting the phone's camera take in the small room. "Holy - Ryan, where the hell are you?"

"I told you, we're at her apartment. A little room at the back." Ryan panned the camera again, struggling to hold the phone level in his trembling hand.

The room was festively decorated as an infant's nursery, complete with crib, rocking chair, diaper-changing table, clothes dresser, and a bookcase already filled with baby books. The walls bore cheery animal patterns and framed prints, the floor a woven rug. An elephant-themed mobile hung over the crib.

In almost every way, it was identical to the nursery that Castle and Beckett had set up for their baby. Ryan recognized it because they had taken pictures, and Beckett's Aunt Theresa had posted them on Facebook. The only thing missing from this room was the set of carved and painted wooden letters spelling out LILY that the parents-to-be had hung on the wall above the changing table.

"This is seriously creepy," Castle muttered, and Ryan could only nod agreement as he turned the phone so that he and Castle could see each other's faces.

"Yeah. Where's Beckett?"

"She went to lie down." Castle blew out a breath and shook his head. "It's just as well. She doesn't need to see that. I'll tell her about it when she wakes up."

"Okay." Ryan cast one more look around the room, shuddered, and moved back out to the hallway. "Castle... I don't like this, man. This woman is seriously obsessed with you guys... and Lily."

"I know." But to Ryan's surprise, Castle didn't look terrified. His expression was grim, determined, but not panicky. "But she's going down, Kev. This is it. We're gonna get her this time."

"Detective, thank you for coming back so quickly," said Dr. Sutherland as Esposito stepped off the elevator on the maternity ward.

"No problem," Espo replied, following the doctor toward the locked storage room. Aragon was standing by the door, along with the locksmith and a few other uniforms. Since they were both on duty, Esposito greeted his girlfriend with only a nod of his head and a small smile, which she returned. He shook the locksmith's hand and gave him the go-ahead to get started.

"No one seems to know why or when this storage closet was closed," Sutherland explained as the locksmith bent to his task. "The nurses say that some number of weeks or months ago, the supplies were all moved out to the other supply closet and the Do Not Enter sign went up on this one. But no one in hospital administration has any record of ordering it to be closed."

"There you go," the locksmith said, straightening up and turning the handle. The door swung open, and they all gasped.

"Oh God!" Sutherland exclaimed, pushing past Esposito to rush into the room. The locksmith turned away, covering his mouth with a hand.

"I'm gonna guess that's the real Susan Murphy," Espo commented with a wince, as the doctor bent over the motionless woman strapped to the gurney.

Aragon and the other uniforms nodded grimly. "Yes, Detective, she matches the photo we were given," one of them confirmed.

Sutherland's fingers pressed into the woman's neck, seeking a pulse, but it was clear to everyone that he wasn't going to find one. Susan Murphy was dead.

As the initial shock passed, Esposito and the uniforms entered the storage closet, looking around cautiously. The shelving racks had been pushed against the walls, empty and bare. In one corner a small table held several pairs of handcuffs and a variety of medical instruments, including several syringes and a number of small bottles of liquid.

The gurney, with its attached restraints that were currently holding Susan Murphy's body in place, stood in the middle of the room alongside a wheelchair - also equipped with restraints - and a plain folding chair.

"This is creepy," Aragon said under her breath, and Esposito grunted agreement as they moved carefully around the small space, trying not to disturb anything before CSU arrived.

Dr. Sutherland had gone to the doorway to summon help, and as two orderlies arrived to remove the body, Esposito called the doctor over to the table in the corner.

"Check this out," the detective requested. "What's in these little bottles?"

"Hmm..." Sutherland picked up one of the small vials and squinted at its label. "Succinylcholine. Oh my."

"What's that?"

"It's a powerful sedative," the doctor explained. "It renders the patient incapable of physical movement, but still conscious and alert."

"Could this be what killed her?"

"Well, obviously I can only speculate," Sutherland replied, "but it can certainly be fatal if a large enough dose is given." He placed the vial back on the table, frowning down at the array of identical vials. "There's quite a lot of it here. This is enough to dose at least two or three people, I would say."

"Javi," Marisa called from the other corner. "Look at this."

"Excuse me," Esposito said to the doctor, and moved around the table to see what Aragon had found.

A small calendar was taped to the wall, displaying the current month. In bright red ink, a large X had been drawn over a single date, one week ago.

"Is that-" Espo lifted his eyes from the calendar to his girlfriend's face, and she nodded solemnly, confirming his suspicion.

"Yep. Captain Beckett's due date."