On arriving at the precinct, Castle headed down to the morgue to collect his jacket. If he didn't go now, he knew he would forget.
"Hey, Lanie," he said when he saw the medical examiner leaning over the body of Lloyd Davidson.
"Oh, hey Castle," she greeted, not taking her eyes off the corpse in front of her. "Your jacket's on the table there."
"Thanks." As he walked further in to the room, he realised it felt very stuffy. "Jeez, don't you have any air-con in here?" he asked.
"The ventilation system is broken," she explained.
"Isn't that like against health and safety?"
She looked up from the cadaver to give Castle a disdainful look. "I don't think broken ventilation is gonna harm them," she said, gesturing towards the bodies surrounding her.
Castle laughed. "Found anything new about the biologist?"
"Nope, cause of death was what I expected, the strangulation. Although he does have a weird combination of drugs in his system."
"Illegal drugs?"
"No, but his medical records don't show any ongoing prescriptions so he was obviously self-medicating. I'll have to run some tests on the other drugs to see if I can find out what they are."
"Awesome," he said, and immediately regretted it. Lanie raised an eyebrow at him. Alexis had told him several times that he was too old to say 'awesome', but sometimes it just slipped out. At least he hadn't given her a double thumbs-up at the same time.
"Thanks, Lanie, keep me posted on the drug results," he said, in an authoritative voice. Lanie just continued to look at him like he was mad. "I'm doing Beckett," he explained.
"About time too," she said, turning back to her corpse.
"What? No, I meant I was impersonating her," Castle said, suddenly feeling a little hot under the collar.
"Mmhmm," she said, smiling knowingly to herself.
Castle gave an awkward laugh, and hurried from the room.
When he arrived at the interview room, Beckett had already started interrogating the suspect. Esposito and Ryan were standing watching the conversation through the one-way window.
"Have I missed anything good?" Castle asked.
"Yeah," Esposito replied. "Beckett took her top off."
"She –" It took Castle a couple of seconds to realise he was joking. "Very funny."
"This guy was one of the biologist's, Davidson's, co-workers," Ryan explained. "He's some kind of intern technician."
Castle surveyed the suspect for a moment. He didn't look much older than twenty-five. He was skinny and nervous looking; hardly the type to strangle a man to death with his bare hands, but if Castle had learned anything since arriving at the NYPD, it was that you couldn't disregard a suspect based on their physical appearance. He had seen small, pretty blondes be convicted of the most brutal murders and enormous, burly, tattooed men found to be completely innocent with a passion for knitting mittens.
"Why didn't we interview him with the rest of the co-workers last week?" he asked eventually.
"Because he conveniently went off the radar for several days – no one had seen or heard from him since Tuesday," Ryan said.
"He disappeared on the day of the murder?" Castle asked, raising an eyebrow. "That's pretty suspicious."
As he watched, Beckett stood up from her chair and slammed her hands down on the table in front of her.
"I'm not going to ask you again, Greg" she hissed menacingly. "Where have you been since Tuesday morning?"
"Just working," the suspect muttered.
"Don't screw with me, Greg," she said, her voice rising. "We know you haven't been at work all week."
"I've been working for someone else," he said.
"Really?" Beckett said, scathingly. "And what's his name?"
The suspect squirmed uncomfortably under Beckett's hard gaze. "I don't know..." he muttered.
Beckett gave an incredulous laugh. "You expect me to believe that? Let me suggest an alternative explanation. At midday on Tuesday you arrived at your colleague Lloyd Davidson's apartment looking for something important. When he wouldn't give it to you, you hit him on the back of the head with a chair then strangled him to death - "
"What? No! I didn't kill anyone! Davidson was my friend!" he interrupted, looking panicky.
"Well, with an alibi like yours, there isn't a jury in the world who will believe you're innocent." Beckett said. She straightened up, tucked her hair behind her ears and turned to leave. "Have a nice murder trial."
"Wait! Wait!" he called after her as she was about to reach for the door handle.
"Damn, she's good," Castle whispered. Ryan gave a poorly disguised snort of laughter.
"What?" Castle asked.
"Would you just tell Beckett already?" Esposito said, rolling his eyes.
"Tell her what?"
"That you lo – " but before Esposito could finish, the suspect started spilling the truth.
"His name is Harvey Baxter!" he shouted quickly. "He told me that he was a friend of Davidson's and that Davidson had recommended me because I'm good at fixing things."
"Give me the address of Baxter's shop."
A few minutes later, Beckett emerged from the interview room.
"Esposito, would you run this address for me?" she asked, handing him a slip of paper. "And check Greg's alibi. See if you can place him there every day since Tuesday morning."
"Got it," he said.
"Hey Castle," Beckett said, smiling.
"Hey! So what are we doing now?" Castle asked, excitedly.
"Well, if Greg's alibi checks out, we'll go down to this repair shop and have a word with the owner, Baxter."
Ryan was standing behind Esposito as he worked quickly on his computer.
"Hey, Beckett," Ryan called. "The alibi checks out."
"Seriously?" Castle asked, approaching the computer. "His story sounded like a load of hooey!"
"Well, it was true," Esposito said, looking as surprised as Castle felt.
Esposito continued, "there are two cameras outside the neighbouring jewelry store and one of them shows the entrance to the repair shop. Look," he pointed to the fuzzy black and white image, "there's Greg opening the shop at nine on Tuesday and closing up at six that night."
Esposito rapidly skipped through the video footage.
"And there he is doing the exact same thing on Wednesday... Thursday and... yup, same again on Friday."
"So there's no way he could have killed Davidson at midday on Tuesday because he was on the other side of town looking after Harvey Baxter's shop." Castle concluded.
Esposito nodded.
"So what was so important that Baxter had to leave his shop in the hands of a virtual stranger?" Beckett asked. "C'mon Castle, we're going to find Baxter. If he knew Davidson, he's a possible suspect."
"You aren't going to see anyone," came a voice from behind them. They both turned to see Captain Gates emerging from her office.
"Captain?" Beckett asked, looking confused.
"The New York Supreme Court and City Hall have just been put under quarantine for this flu virus. Three people are already dead," she said, looking grim.
"That sounds like a pretty nasty virus."
"Yes. The virus is somehow being distributed only in public buildings across the city."
"But that makes it sound like – " Castle started.
"Be quiet, Castle," Gates cut across him. "This is now being treated as an act of biological terrorism."
"That's what I was gonna say," Castle muttered to Beckett. She tried to stop herself smiling as the Captain glared at Castle.
"I need every single team on this case now. Everything else can wait."
"Yes, sir," Beckett said as the Captain strode away from them to answer her phone.
"Esposito, Ryan, you up for a trip to an infection zone?" Beckett asked.
"Ah, the question every man wants to hear on a Saturday morning," Esposito said. Ryan smiled ruefully.
The three detectives collected their coats. "I'm coming too, right?" Castle asked.
Beckett hesitated. "Castle I – "
"Come on, I signed a waiver, bring on the danger."
Sighing, she agreed.
As the four of them headed towards the exit, the Captain came running back out from her office.
"Wait!" she shouted.
They all turned to look at her.
"You can't leave. They think the precinct is at risk from the virus. Esposito, turn the news on."
Within seconds, Esposito had the news playing on his computer.
"Two more buildings in the Manhattan area have been put under quarantine by the Department of Health this afternoon following the outbreak of a flu virus. A Department of Health official has told this reporter that the mutated flu virus is being released from modified air purifiers which have been hidden in the basements of public buildings. From what we have heard, the virus is being distributed from the basements and spreading through the ventilation systems.
"It is not known how many more places may be at risk from this extremely aggressive strain of the virus, but officials are urging the public to stay away from community buildings until the outbreak has been brought under control.
"Although it has yet to be confirmed, it looks as though this is being treated as an act of biological terrorism.
"The development of severe flu-like symptoms should be reported immediately to the emergency services."
The sound of the door banging open made Beckett and Castle both look up from the computer screen.
"You gotta be kidding," Beckett breathed, as twenty men in hazmat suits burst in to the room with Department of Health plastered across their outfits.
"Ladies and gentlemen please do not panic but this building is infected with a potentially deadly virus," one man shouted. "I am going to need your full cooperation to minimise casualties."
"I get the feeling this day is going to go downhill," Castle muttered.