The trip to the morgue from Calliope Thrace was a short one; it was one of the perks of working a murder scene in Midtown-South. Within fifteen minutes Beckett and Adam were nearly jogging as they stepped off the elevator and booked it into Shane's autopsy theatre. Wayne Hill's body was on the stainless steel table, naked and open mid-Y cut while Shane spoke his notes aloud into his Audiovox as he took out the heart and the lungs.

'Pause record,' he said clearly, then waited two seconds before hearing the beep he was no longer recording his voice when he looked up at the live bodies arriving in his work space. 'Detectives, thanks for getting here so quickly.'

'Your message was marked nine-one-one, that tends to make cops move quickly,' Adam replied. 'What's up?'

'I have a cause of death for you, confirmed.'

'Already?' Beckett blinked like an owl. 'Dude that's pretty damn quick.'

'I told the lab I was bringing in a priority case, had them waiting to draw blood samples and I put a rush on the stomach contents. It's not usual procedure but like I said, priorities.' Shane stripped off his latex gloves, went to his bench for the preliminary report. 'Stomach contents are whole wheat toast, bacon, mayonaise, lettuce, tomatoes, Monteray Jack cheese, grapefruit juice, coffee black, and peanut oil.'

'Peanut oil?' Beckett repeated, and Shane nodded vigorously.

'Two fluid ounces of one-hundred percent pure peanut oil, the kind you get from any grocery store and used to make really greasy, really tasty French fries at home. I took tissue samples and blood work, and both indicate anaphylactic shock from peanuts as the cause of death.'

'How would he not notice that?'

'Based on rate of digestion, it was mixed in with the coffee and ingested five minutes before his time of death, which as I said on scene is pin-pointed to nine-thirty this morning.'

'Coffee is bitter, it would have masked the smell, the taste, and you wouldn't notice until it was too late,' Adam reasoned and Shane tapped the tip of his nose.

'Bingo. Whoever did this had to know he had a severe peanut allergy, the kind that if he ingested it meant he was a goner, EpiPen or not.'

'There were no signs of an EpiPen or TwinJect on-scene,' Beckett said, made a note in her scratch-pad. 'An allergy that severe he'd carry one with him at all times, like Dell and his insulin.'

'Bingo times two.'

'Which means that our killer may have taken it with them.' Beckett frowned in thought, looked over at Adam. 'Get on the phone to Leung at the school, tell her we need a list of all visitors or guests to the school. They would all have to be apprised of a peanut allergy.'

Adam nodded, left to make the call; alone with his mother-in-law Shane cocked his head to the side. 'You're not thinking it's an outside job, are you Kate.'

'No, I'm not.' The fact Shane put it as a statement, not a question, showed just how well they worked together. 'The timeline that one of the witnesses, Sarah, gave us, it's too straightfoward and too...precise, I guess is the word for it, too precise for there to be enough time for a stranger to the school to get in, find his room, poison his coffee and be out again all without being noticed.'

'So someone at the school poisoned the teacher? Why?'

'That's my job, to find out why,' she said, then glanced over when Adam came back in. 'Leung come through?'

'Yeah, she was already going to give us the list anyways. She also said she'll have the other files to us by five today, and she gave the school security logs to Harold for the computer side of things.'

'Good.'

'Something else is bugging me,' Adam said, scratching the back of his neck. 'Sarah said when Nicky came in he looked angry about something, right?'

'Right.'

'Well, we know he had a beef of sorts with Hill, but if anything, having to wait would make you edgy and anxious, not angry. So what did he have to be pissed off about?'

'A very good point. Shane you got anything else right now?'

'No. I'll have a more thorough report for you once I get his workup completed, maybe another two hours or so.' Shane went to the box on the wall for fresh protective gloves, a subtle signal that he had to get back to work so Beckett and Adam thanked him, left at a slightly slower pace than the one going in.

'Adam,' Beckett said to him when they were in the elevator. 'If you've got a prejudice against this investigation because of your own experiences now is the time to say it.'

'Hell no. I'm just trying to figure that kid out.'

'Good.' But Beckett knew she'd be keeping an extra close eye on him for this one. 'Feel like having a little lunch now?'

'No BLTs for me, thanks,' he replied with a little humour, then added after a beat, 'and no peanut butter sandwiches either.'

They opted for Monsoon's so they could make it a working lunch and each was careful to avoid anything with peanut sauce; it was just too weird to think about it while investigating a murder by allergic reaction. with boxes of pad gra prow and cashew chicken curry, they set up the murder board and broke down their timeline to a very specific minute-by-minute scale instead of the usual hour-by-hour.

'Would a school like that have security cameras?' Beckett asked Adam.

'They might, but more likely they'd have secure entrance by pass-key.'

'How woudl that work?'

'All exits are locked from the outside, and you have to go to the main entrance, then be issued a guest card as well as signing the visitor's log.'

'Sounds a little like prison.'

'Welcome to my high school years,' Adam said with a sour smile, then looked back at the board. 'I still like that kid for it.'

'What, the high school kid?'

'Yeah. I remember reading in the papers about one of your first cases with Castle, the kids at Redding Prep who decided to play at being bad-asses and ended up with two of them dead.'

Beckett had thought of that one too, and the similarities were hitting close to home. 'Well, just because he was murdered at the school doesn't mean it was school-related. That could have been opportunity. We need to speak to his husband, neighbours, anyone who saw him during his school morning routine.'

She spun away from the murder board to answer her ringing phone. 'Beckett.'

'Detective? It's Sarah Ritter, from Calliope Thrace?'

'Sarah, yes I remember you. What's up?'

The girl gave a little sigh. 'I told my parents I thought I might have had something with peanuts in it, and they dragged me to the hospital and the doctor says I was exposed to peanut oil some-time this morning.'

'What hospital are you at?'

'Saint Vincent's, since it's closest to my school and-'

'I'm going to send Detective Brennan, he was with me this morning, to talk to you, your parents and your doctor. Don't move, he'll find you.'

Beckett hung up, threw a wad of paper at Adam's head to get his attention. 'Detective, you need to go talk to Sarah Ritter, she was admitted to Saint Vincent's with signs of anaphylactic reaction to peanuts this mornin.'

'On it.'

'Oh and try not to bang your almost-wife in an empty on-call room.'

Adam just grinned. 'Wouldn't dream of it, Beckett.'

The wait at the hospital was slightly longer, even with a flash of the badge to the desk nurse - an outbreak of hayfever had sent everyone and their mothers running for the fast-track clinic and ER, meaning all medical staff was overrun with the sneezing and sniffling.

Finally, after nearly forty-five minutes of waiting Adam saw the doctor coming towards him.

'Detective, my apologies, it's been a busy morning. This way.'

'What can you tell me about what caused Sarah to have the reaction?' Adam asked as he followed her towards a treatment room.

'It was nearly pure, without preservatives, which means that she didn't accidentally ingest it with something she ate. This was an airborn irritant, more than likely she was in an area where peanut oil had been used.'