Almost having his throat cut open had not been on Bilbo's to-do list that evening.

He just thought he'd stop by at the safehouse after having dinner to find out whether anyone had any idea as to what their next course of action would be. And when the code he'd been given by Dís to open first the electric lock on the gate and then the door both worked, he thought everything was perfectly fine.

Right until he entered the house and Thorin snuck up on him and put a knife to his jugular. That had been a bit of a damper on his afternoon.

Quite a fascinating knife, too. Very ornate. It even looked sharp.

It was retracted quickly enough, but he stood frozen for a few seconds anyway. 'Ah… We're really going to have to talk about this tendency you have of threatening me with sharp objects.'

'Apologies,' said Thorin, making the knife disappear who knew where. 'I didn't know it was you.'

'Well,' said Bilbo, with patience you could have bent a crowbar around, 'Considering that I used the code to get in should have been a clue.'

'I was watching the security feed when I saw the gate open,' said Thorin, ignoring his obvious ire.

'All the more reason not to cut my head off.'

'You weren't on it.'

'Wait, what?'

Thorin gave him a look. 'You didn't show up on the screen. It looked as if the gate had opened by itself.'

'That doesn't make any sense! Could it be a, a glitch or something?'

'A glitch that only cuts hobbits out of the frame?'

'All right, Mister Sardonic, you tell me what it was.'

Apparently the rest of the company had gone too their respective homes, and Dís and her sons were out on various business, so they went back on their own to look at the CCTV. There, Bilbo saw with his own eyes, or rather, didn't. 'Switch to the cameras in the hallway,' he said, and was almost chagrined to find that there he showed up as clear as day.

Thorin shook his head. 'Something is off.' Playing back the feed from the front room, they watched it, puzzled and slightly creeped out.

'I look like I'm talking to myself,' said Thorin. He paused. 'I'm not hallucinating, am I?'

'Um… Have you ever hallucinated?'

'Not the last thirty years, give or take.'

'Well, no use starting now, is there?'

He contemplated this, and nodded in concession. Then he said, 'What changed between the front room and the hallway?'

'Uh…' Bilbo looked himself over. 'I took my coat off?'

'Then go fetch it.'

Grumbling mildly, but doing as he was asked (or more accurately commanded), he returned to the room to find Thorin frowning even more deeply than was usual. 'What do you keep in there? You disappeared from the cameras again.'

Going through the pockets, he pulled out his keys, his small set of lockpicks (just in case), and the strange device given to him by the mad inventor in the Goblin King's warehouse. He'd altogether forgotten about it.

Thorin furrowed his brows. 'Is that a radio alarm?'

'I think it may be made from the leftovers of one. Hang on, let me see if this is it.'

It was. They stared at the device. They prodded at it. On its side was a very simple on/off switch, and what seemed like no other way to operate it. Thorin sat back, and pulled out his phone. 'Fili? Go find Kili, we've got something strange here. No, he won't pick up his phone. Yes.' He hung up, and trained his gaze on the device. Half-turning to Bilbo, he said, 'You realize what this could mean for us?'

'Seems we might not have to worry about the surveillance cameras during the heist. If this isn't some sort of a fluke.'

It was an irritated looking Kili that arrived with his brother, but when they showed him the device, his interest was immediately caught.

'I've never even heard of anything like it,' he said. 'Well, there was a rumour some years back that the private sector was trying for something that could disrupt laser trip wires, but that never went anywhere as far as I know.' Carefully unscrewing the lid over the power source, he added, 'It runs on a crystal battery, too.'

'That impossible,' said Thorin. 'We never even got the chance to put those on the market.'

'Mm, that was what I was thinking.' Seeing the look of confusion on Bilbo's face, Kili explained. 'Crystal batteries were something Thrór had been developing. He only made one prototype, and from what we've heard, Smaug's been trying to get his brainiacs to reverse-engineer it ever since. Unsuccessfully.'

Thorin looked darkly smug. 'It was the finest work my grandfather ever did. And since the blueprints for the project… Mysteriously disappeared, along with several other important documents, he will have to try for a hundred years before he gets anywhere.'

'Which is why it's so strange this thing runs on it,' finished Kili.

His brother leaned over the table to get a closer look, and said, 'There's something written on the inside of the casing.' He squinted. ' The Research Institute Engineering Guild. Ever heard of that?'

Kili shook his head. 'What I want to know is, how did someone working for the Goblin King have the materials, or the skill to make something like this?'

'Maybe he stole it,' said Fili, and sat back. Then he squinted at his brother. 'Have you done something with your hair?'

Kili hesitated, and looked momentarily guilty. 'Is this some kind of a weird human compliment you've picked up from watching too many soap operas?'

'Your braids look weird. And if you'd just watch them with me you would know they're awesome.'

'Back to the business on hand,' said Bilbo, interrupting them, 'Do you know how it works?'

Kili shrugged. 'I mean, I could hazard a guess, but not without much longer time to take it apart, only that might mean it wouldn't work when I put it back together again.'

Bilbo looked at Thorin. 'Is it safe for us to use it when we don't know how it works?'

Thorin hesitated. 'I don't know. But I think it would be foolish of us not to take this chance.'

'Indeed, I agree.' They all jumped, but relaxed at the sight of Gandalf in the doorway.

'How did you get in?' asked Thorin accusingly.

The old man leaned his cane against the table and took a seat. 'I got the security codes from your sister. She says not to overexert yourself in any way, I was told to add.'

'I'm not,' said Thorin sullenly, but Bilbo could see that he was breathing carefully, his ribs apparently troubling him.

'Hang on, we haven't seen you for ages!' He said to Gandalf. 'Where have you been?'

'Not idle,' said Gandalf. 'I have been asking around, and have found out that there is an upcoming expo of technology at the Lonely Mountain next week. And I think that may be our best time to strike.' He looked very pleased with himself.

'Why then? It will be full of people!'

'Meaning the focus will be on them, and not the vaults where what we seek is kept.'

Bilbo looked back and forth between each of them. 'I probably should have asked this sooner, but what specifically is it that we seek?'

Fili raised an eyebrow. 'You mean no-one told you?'

'Remember the crystal battery?' said Kili. 'It's the prototype that we want.'

'Can't you use this one?' asked Bilbo, pointing at the shimmering heart of the device.

Kili shook his head. 'This one is just a small power source. The prototype is more than a battery, really. Potentially it could store unbelievable amounts of information, power anything from this tiny thing here,' he gestured to the cloaking device, 'To the entirety of the city centre. Perfectly clean energy, too. If we could reverse-engineer it with the help of the plans we already have…'

'My grandfather called it the Arkenstone,' said Thorin. 'He had something of a flair for the dramatic. If we can get it back, we can effectively get the financial backing to put them into production and Smaug out of business.

'So it's a case of 'revenge best served cold'?'

Kili shrugged, his attention again on the device. 'It sounds better in the original Klingon.' Noticing the stares he received, he scratched the back of his head in embarrassment. 'Sorry. Nerd joke.'

'Couldn't Smaug sue you for theft of mental property, even if he couldn't prove that we stole the prototype?' asked Bilbo.

Thorin shrugged. 'He could try, but if we do our work entirely within the dwarf community, he won't be able to get at us until it's completed, and with any luck everyone will be too eager to get their piece to pursue it too much.'

Thinking that plan had way too many gaps in it for comfort, Bilbo nevertheless said, 'Guess we better get started, then.'

Author's note:

Over six hundred views and only a single review? Shame on you, dear readers.

The so-called 'crystal batteries' in this story have nothing to do with actual crystal batteries. Really I just used that name because it sounds cool (and goes with how I imagine the Arkenstone looks like.)

Someone commented that Thorin seems very high-functioning even with his diagnosis, which actually comes from a lot of factors, such as the fact that he's on medication that works for him (which took a long-ass time to find and hadn't actually been invented when he was first diagnosed), although it's a part of the reason he's so deadpan all of the time (when not taking it, he'd be more prone to anger). Then there's the fact he's been dealing with it for forty years (luckily his therapist is a dwarf and so isn't, you know, dead). His manic/depressive episodes happen about once-twice a year, but are much less severe than when he first began to experience them. (The hallucination line wasn't a cheap joke - it really was that bad for a while.)
Then there's the fact that, despite what TV tells us, mental illness is not the single defining trait of a person. Bilbo might not be able to imagine living Thorin's life and thinking of it as normal, but that's still what it is, because Thorin has adapted to it.

Cosmological constants:
-Shakespeare
-Star Trek
(The 'millions of monkeys at millions of typewriters' hypothesis becomes a billion times more interesting when you realize that actually, that's exactly what happened.)