Chapter 1

Kate Beckett was not, most emphatically not (she insisted to herself) a ghost.

For a start, she wasn't dead. She thought she might have noticed being killed, seeing as it was usually pretty obvious if someone was murdering you; and she was only twenty-nine, thirty next month, so unless she'd been truly and undetectably unlucky, she hadn't died of an aneurysm or similar and simply not noticed.

Secondly, she was solid. If ghosts had existed, which they equally emphatically did not, they were never solid. Just because she could quietly and unobtrusively dissolve into a little swirl of sparks, which faded in an instant, or control it so that she never bumped an arm on a doorframe, didn't mean she was ectoplasmic. She wasn't. She was entirely solid, most of the time. Unless she wanted to be not solid. Unsolid? Insoluble? Nope, that was science, which she had happily forgotten as soon as she could. Whatever. In any event, she needn't be solid if she didn't want to be, which had advantages, and didn't need to be visible if she didn't want to be, which also had advantages.

All of those advantages had, entirely ethically, helped her to her present position and success. What they had not helped her to was a boyfriend or lover or even a date, for God's sake, who wasn't an utter waste of space and/or chauvinistic asshole. Take a bow, Will Sorensen. And then take a long hard hike to the far side of the Moon, without oxygen. Boston wasn't nearly far enough.

So here she was. Twenty-nine, single, massively successful, and (though she didn't like admitting this either) lonely. She knew how to deal with that. Bury it under two pints of coffee-chocolate ice cream, with coffee sauce, and coffee laced with vodka. The last would preferably be taken in a nice hot bath, with plenty of bubbles. If she really tried, she could half-dematerialise and end up with the bubbles perfectly stuck to her, which (after enough vodka-laced coffee) made her giggle. She didn't have a lot to giggle about.

Some months later, giggling was the very last thing on her infuriated mind. She'd been sandbagged into having the indescribably annoying Richard Castle shadowing her, and what was absolutely the worst thing was that he was unbelievably sexy and she couldn't do anything about it because every single time she thought about it he did something to annoy her. Since killing your sex partner was only for Black Widow spiders, and while she might be not entirely human she certainly wasn't in any way arachnoid, ugh, she couldn't indulge. Which was a really gigantic irritation, since she could really do with a really good night. Or two, or three, or even more. She was sure he could provide a really good night, too, if only because his super-super-sized ego wouldn't allow him not to.

On the other hand, she had absolutely no idea whether she could keep her, um, quirk (that was a good way to put it) under control if she was totally out of control. The problem hadn't arisen with Will. Much like Will, latterly. Hmmm. Oh, well. It wasn't going to happen because she wasn't going to let it happen. Not unless Richard Castle became substantially less annoying. It wasn't like he could get any sexier.

She mentally slapped herself upside the head. Thoughts like that were not helpful. And nor was semi-dematerialising, which had meant that all tonight's lovely bubbles had dropped all over the bathroom floor. Dammit. Now she'd have to wipe the floor. That was all Richard-why-couldn't-he-be-less-of-a-pain-Castle's fault, too, even if he wasn't here. Humph.

Tired and cross, she put herself to bed, and entirely failed to fall asleep, which only made her more irritated. Irritation allowed a tiny, naughty thought to arrive. It said you could see what Castle's like at home.

"No!" she said aloud. Spying on Castle would be…

Interesting. Especially if he weren't fully dressed.

"That's voyeurism. Which is a crime. I don't commit crimes, I arrest criminals."

Shame.

"Shut up." She shut her eyes, and managed to fall asleep. The naughty little voice had clearly ordered the night's dreams, however, since they all involved half-naked Castle. Her morning shower barely made it to tepid, not that it helped.

For once, murders were thin on the Manhattan ground, which left Beckett both bored and subjected to the boredom of others. Specifically, the boredom of Castle, which provoked Espo and Ryan, who were also bored. Beckett could have lived without trashcan basketball for some time, but supposed, bitterly, that at least it wasn't beer pong. She flicked through another cold case, finding nothing that the city had the budget to pursue, and made herself yet another cup of coffee. The machine spat steam at her, and she swiftly dematerialised her hand to avoid a nasty scald.

"You okay?"

She jumped, and the coffee splashed the counter. "Castle! You startled me."

"You aren't scalded?"

"No – just missed me. Thanks."

"Phew. I'd hate to see that beautiful skin damaged – and if you burnt your hand, I wouldn't be able to hold it to comfort you."

"You are not holding my hand."

"Oh, unkind maiden, how cruel thou art."

"This isn't a play." Beckett glared. "I don't have to listen to your flummery. Go away and let me drink my coffee in peace."

"You haven't any coffee, because you just spilled it all over the counter." Castle efficiently wiped it up, and started a new cup brewing. "There. Now you'll have coffee." He handed it to her, began to make himself one, turned around, and found Beckett and her coffee both missing. He hadn't noticed her go. No breath of air to mark her passing, in fact. She might have been invisible. He looked around, and saw her just sitting down at her desk. He took his own mug, and followed her.

"You snuck off," he whined. "That wasn't nice."

Beckett raised the deadly left eyebrow. "Show me where it says I have to be nice to you? I don't think that's in the NYPD Patrol Guide anywhere."

Castle smiled, picked up a piece of NYPD headed paper, scrawled across it, then handed it to Beckett. She stared at it. Detective Kate Beckett must be nice to Rick Castle. Three seconds later she'd scored a perfect three pointer into the trashcan nearest Espo.

"Shot!" Castle cheered.

Beckett's glare demolished the imaginary basketball arena, all the spectators and most of Manhattan. If it hadn't been bound to lead to far too many questions, she'd have dematerialised again. Sadly, Castle's gaze was firmly fixed on her.

Castle felt extremely strongly that Beckett was, in some way, avoiding something, and he didn't mean the scalding steam. He'd been dead sure she'd been in its way, but somehow she hadn't been hurt. Well, a little subtle (he could do subtle, he just didn't tell anyone how) investigation should help. He sipped his coffee, and considered. It wouldn't be hard. He hadn't, as yet, tried to investigate any of the precinct cops, because he wasn't, um, interested in most of them, but his lust for Beckett had only risen (and risen, and risen: he was permanently risen around her) and the two subsidiary characters of Raley and Ochoa had developed. He was, slowly, becoming accepted, but before he made a decision on whether to take his relationship with Beckett to more than over-heated flirting, and before he became good friends with the boys, he'd better check them out.

He'd have solved a lot of problems in his earlier life if he'd done that more often, or indeed at all, but when he was younger he'd still been a little naïve. If he'd checked out Meredith first…but then he wouldn't have Alexis, and she was the light of his life. Thankfully, she hadn't inherited any of Meredith's less desirable traits. She hadn't inherited his, um, peculiar trait either, but that was likely a good thing too. It hadn't brought him much in the way of happiness, though at least it had helped him to avoid plenty of misery.

He supposed, rather pensively, that he should do it before he got in far too deep with the precinct. He could already see that looming: he bounced out of bed with enthusiasm for the day, knowing that he would be there, adding his mite to the investigations; he looked forward to seeing the team: sure, especially Beckett, but all of them. At the end of the day, he could look back on it with satisfaction at having done something useful, and then write with even more satisfaction.

He resolved that he would investigate that evening, and put out of his mind the unpleasant thought that if he discovered something untoward, he'd need to pull back. He didn't like that thought, but it continued to squirm around the lobes of his brain all day.

Beckett vaguely noticed that Castle was lost in thought, but since any peace from his incessant frivolous chatter was (so she told herself, ignoring the slight feeling of being ignored) to be welcomed, she concentrated on the cold case file and absolutely not on the occasional wafts of attractive cologne. Nor did she peep up from under her lowered lashes at him. Of course not. That would be…silly. The scruff was surprisingly sexy, though. It could provide all sorts of interestingly provocative sensations. She focused on the cold case, in the hope that it would cool her overheating brain.

By the end of the day, she'd remained mostly undisturbed by Castle, who'd played with his phone, occasionally asked not-entirely-dumb questions, and come up with precisely zero crazy theories, all of which were so unusual that she'd had a hard time not asking him if he were sick. With amazing self-control, she'd refrained. He didn't need any encouragement. (You should, said her annoying little voice. She ignored it. And then you should take a peek at him at home. We discussed this. It's a crime. Still a shame, and I bet Castle would love you peeking at him. Of course, you'd have to let him peek at you. Not happening. Spoilsport.)

Consequent upon the annoyingly naughty, seductive voice in her head, Beckett humphed her way home, purchasing in passing yet more ice cream. If the voice didn't shut up, she'd need to run a half-marathon every single week to deal with all this ice cream.

If she didn't really, really want to do what the voice said, her life would be a whole heap easier, she thought crossly. She ate her ice cream, and started to run a nice hot bubbly bath. Part way through the running of the bath, she realised that half her irritation arose from the proximity of Hallowe'en. She was always more irritable as the day approached.

Castle had dinner with his daughter, checked that all was well, and repaired to his study, ostensibly to write. He did write, in fact, though he hadn't intended to, as a perfect Nikki-scene fell into his head. That evicted from his brain on to the screen of his laptop, and saved, backed up, and saved again, he began to think. Something in the bullpen had triggered his instincts, and he needed to find out what before anything else happened.

Before he could investigate properly, he needed to collate everything he knew. He actually knew quite a lot, he discovered as he wrote it all down: not just facts, but impressions, conclusions, and extrapolations. He added photos of each of the three cops, and spread it out, making sure that he'd included absolutely everything. There was no room for error: not if he wished for a true outcome.

This close to Hallowe'en, he should have no trouble obtaining a true outcome.

He began with Ryan, who was simplest. He read down all his notes, pictured Ryan clearly, aided by the photo, and then put it all together to form a whole Ryan in his head. That done, he gathered his thoughts, and brought a simulacrum Ryan out of his brain and on to the desk in front of him, which he would use as a focus. He concentrated, and began.

Well, now. Simplest didn't necessarily mean simple. There was a lot more to Ryan than Castle had ever expected, or noticed. His well-honed observation skills hadn't seen any of this. Baby-faced, mild, good Catholic mammy's boy Ryan – had been undercover with one of the gangs for a year, never spotted, never suspected. The gang was now defunct, and it was Ryan who'd brought them down. Wow. He hid that really well.

But he wasn't hiding anything…untoward. Not so much as a smudge. Ryan was clean right through. No nasties lurking in his psyche – nothing but ordinary human, neither good nor bad unusual traits.

One down. Castle dismissed the simulacrum of Ryan with a smile.

Now for Esposito. He ran through the same preparatory steps, popped the simulacrum on his desk – even the figure had Espo's aggressively cocky, take no shit attitude – and began. Espo wasn't simple either, though his background was rather less surprising than Ryan's. Bad start, straightened out in the Army, found he had a talent. Touch of PTSD, which he'd gotten over. Massive dose of respect for Beckett, originally rather against his will. Not like Ryan, who regarded her as an ideal to aspire to – without a single sexual or romantic thought. Espo...would have, if she'd ever given him the slightest encouragement, but gradually that had become siblings-in-arms.

There it was: the relationships that had been puzzling him. They were family. Bossy sis: driven, alpha, ambitious, organised and always in control, tough, fighting brother, baby brother, happy to trot along behind but capable of astonishing feats for all that he never advertised it. More or less, that was their team. He scrawled that down, for later Nikki-use, and then dismissed Espo, who, like Ryan, didn't have a single good or bad untoward trait.

So, both the boys were as normal as normal could be. He, Castle, could safely be friends with them, if he were acceptable (and he was pretty sure he was, because they joked and jabbed at him just like they did with each other, and now he needn't worry that they were hiding anything), without a qualm.

He looked at his watch. Eleven-thirty. Midnight had power, though why he should think that he really didn't know, since the chance of Beckett having any appalling secrets was somewhat less than the chance of his surviving being dropped from a cruising-altitude passenger plane without a parachute.

He was at the point where he had to decide. He was enormously attracted to Beckett, but he could step away from that if he had to. But if he were to go all in, he needed to know the truth of her, and he wanted to go all in. Honestly, he was almost there already, and this was his last chance to stop, before he could end up in another disaster. If he'd checked out Meredith, he'd have known she was faithless; if Gina, he'd have known that it would never work. Neither, though, had had the slightest tinge of anything odd.

That left Beckett. Beautiful, brilliant, blazing Beckett. He'd never previously Looked at her, and doing so felt unpleasantly like betrayal. But he had to know. All his instincts, intelligence, and gut told him that she was true right through – but that didn't mean she was.

He had to know. If he were wrong, it would shatter his heart – but not his soul, not yet. If he didn't know, and went all in, and were wrong…he'd never recover.

He had to know.

Before him, he built his Beckett: precise in every detail; set her simulacrum to be a perfect, poised replica, and focused his will and talent.

An odd inheritance, this. Presumably, it had come down his father's line, whoever his father might be. It hadn't come from his mother, and, thank God, it hadn't passed to Alexis.

Witchfinder.

So far, he hadn't found anything that might be a witch. Even following Beckett around, the cases were nasty, but human. He'd Looked.

"You're wasting time," he said aloud. "Get on with it."

He took a deep breath, and Looked.

What the hell?

Beckett, luxuriating in her lovely bubbly bath, sipping her coffee (not wine or vodka today), was idly playing with the bubbles, sliding her hand through them without popping them, putting her cup down to dissolve into sparkles and reform. She'd more or less decided that she should investigate Castle's home behaviour, naughty as that would be, because her well-hidden curiosity was driving her utterly crazy, and besides, she really wanted a good look at him out of his clothes.

She knew she shouldn't. But…aw, dammit. She'd been worried about him when he was so quiet and thoughtful all day. It wasn't normal or Castle-like, and…well, it had been sweet. She liked sweet, once in a while, and it was definitely a major plus if Castle could manage it.

She sploshed happily, and contemplated. Yes, he was incredibly irritating, but every so often he showed a good point, and today's touch of vulnerability had left her with a deep urge to comfort him. Besides which, Castle believed in everything, so he'd be utterly delighted to find out that she could dematerialise.

She reluctantly exited her cooling bath, dried off, moisturised, and snuggled into bed, where her plump pillows, soft cotton sheets, and cosy quilt made her delightfully happy. She drifted off into sleep perfectly contentedly.

Just on midnight, she woke with a bang. How could Castle be in her room? She slapped the bedside lamp on, and stared around. No-one was there. But she'd felt him. He'd been standing right there at the end of the bed, and then he'd sat down on it, bent down and kissed her. She did not do Sleeping Beauty. Her cosy comfort disintegrated in a flash of fury. Well, if he was rude enough to manifest in her bedroom, she was going to retaliate in spades.

She stormed out to her main room, slammed down on the couch, and shivered furiously into a little swirl of sparks, gone as soon as the night sky looked at them. Not ten minutes later, she ghosted through Castle's study window.

What the freaking hell?

She fled as fast as her invisible self could go, and was home in considerably less time than she'd taken to get there. A fast shot of chilled vodka later, she'd almost stopped shaking.

Castle was a Witchfinder?

Thank you to all readers and especially reviewers.

This is a piece of Hallowe'en silliness, in 7 chapters plus a very short epilogue. Posting Sun/Tue/Thu, with the epilogue on Hallowe'en itself. I suggest you all brush up on your myths, because this one draws from several.

The final chapter is M-rated.

As has become my habit, I encourage those of you who haven't read my original books, or who haven't read all five currently published, to read them or catch up. They're the Casey&Carval series, on Amazon under SR Garrae. Death in Focus, Camera, Sight, Frenzy, Lights. A sixth is in progress.