"John, what do you make of this?"

In the span of about a minute and a half of excited running, Sherlock and the newcomer who called himself "John Smith" had created quite the destructive mess in the kitchen. John didn't even know where to start, what was safe to use to clean things up with, or whether half of it should go in its own special biohazard bag or not. He listened in on the conversation as he picked up the broken fragments of containers he could identify as glass or plastic and washed them off to toss out. This could potentially take hours. Luckily, that was about as much time as he seemed to have, since Sherlock's interview sounded like it was rapidly going nowhere once past name and occupation. They seemed to have been discussing some form of identification issues when Sherlock had called out.

"Hm?"

At the summons he laid down on the counter a large piece of a glass jar quite similar to the ones he'd been carrying that morning and popped his head into the front room again. Sherlock was sitting across from their guest, one leg folded over the other, the gun resting on its side beneath his fingertips on the edge of the arm rest. He was waving a black leather booklet slightly in John's direction. The man took it and opened it. Inside was what appeared to be a cross between an official photo ID and a business card. It seemed like a government issued plumber's license.

"It looks like some credentials for a Mr. John Smith, plumber."

Sherlock studied Mr. Smith narrowly. Mr. Smith smiled pleasantly from one man to the other.

"You see?" he asked lightly. "Now can I please get on with my work?"

Sherlock raised his eyebrows and adopted a light, sarcastic tone. "Certainly but...there are a few problems, Mr. Smith." His tone dropped down darkly again. "Problem number one, there's no such thing as a plumber's license, if that's what you're trying to offer us as proof." Mr. Smith's smile faded to something more nervous again. Sherlock continued. "There are NVQ certificates, but whatever that is...is entirely fabricated."

John frowned and studied it closer. "It looks fairly official."

"Does it?"

Sherlock held out his hand, took it back, and flipped it open, tilting back and forth slightly. His eyes flickered around the paper momentarily, then he closed it and tossed it a bit short back to their guest. The man almost caught the booklet on the very tips of his fingers, but dropped it at the last second and had to bend down to pick it up.

"You know, you're not a very pleasant person," Mr. Smith commented lightly, sitting back again and tucking the booklet inside another breast pocket.

"Problem number two," Sherlock continued, ignoring him, leaving the gun balanced on the arm rest, and steepling his own fingers in front of his chin, "is that slip of paper itself, regardless of what you were trying to pass it off as. Tell me, how did you do it?"

Mr. Smith smirked uncertainly, looking from one man to the other. "How did I...do it?"

"Yes. I don't know how you've done it-"

"-Done what?"

"-But somehow you've hypnotized my colleague."

John frowned at Sherlock. "What?"

"Perhaps it was when he leveled the gun with your head; perhaps it was when you were walking with him back to the room." Sherlock was in rare comment-ignoring form, and folded all of his fingers together save for his right index, which he left up in a point-making gesture. "Perhaps it was even when we first discovered you in the kitchen itself. Perhaps you had opportunity then to induce in John some form of hypnosis that you either hadn't the time for concerning me, or had simply failed at attempting. For you see, I see nothing on your little paper trick, Mr. Smith. Just a few holographic wavy lines on a blank background."

It was difficult to say who was more surprised, John or Mr. Smith. John spoke first, though.

"I'm...sorry, what? You didn't see the license?"

"No." Sherlock drew out the word as he turned to look at John. "I would be very wary of listening to anything he says, John, and also I would suggest returning to the kitchen until I have figured this little trick of his out. Are you certain you saw some sort of credentials?"

John nodded, looking not particularly certain at all. He didn't make any movement to go back to the kitchen though. "It was a photo ID with his name and a certified license for working with the plumbing of a house, with a specialization...in...frozen pipes..." Saying it out loud made it sound slightly ridiculous now that he knew it had been somehow fake. "Can I see it again?"

Sherlock raised his eyebrows expectantly at Mr. Smith, who shook his head and smiled.

"Sorry, one-time only." He was clearly not taking any of this seriously despite being a captured criminal.

With a short exhale and an abundance of impatience, Sherlock picked up the handgun left on the edge of the chair and pointed it at Mr. Smith. Their guest made a dramatic eye-roll and pulled out the booklet again, muttering something about guns. Sherlock took it from him with a curt thank-you and handed it to John, who opened it and studied it very closely.

Sherlock lowered the gun back to the chair's edge refolded his hands.

"So why don't we cut to the chase, Mr. Smith, what agency do you report to?" he asked.

"...Oh god, where did it go?" John muttered quietly. "It's just blank..."

"It's fading?" Sherlock asked opver his shoulder. "Good, perhaps the hypnosis can be broken..."

"Hold on," Mr. Smith interrupted, "agency?"

Sherlock's head snapped back to his guest quickly. "Yes. If you had even made the slightest attempt to look like a plumber, I might have thought Moriarty was sending some form of probe into my life, though I highly doubt he'd even be that obvious. Since you aren't particularly subtle about this and have clearly underestimated my perception and intellect, it's clear you're not one of his , we're left with a bit of a blank. So, which agency is scrutinizing me this time?"

Mr. Smith looked around the room as if seeking some kind of audience, laughing. "D'you think I'm a spy? I'm not from any agency."

Sherlock had little time or care for his display. "Could I see that device you were brandishing at the microwave earlier?"

"What, this?" Mr. Smith pulled the flashlight-looking thing from inside his jacket and waved it slightly.

"Yes." Sherlock held out his hand once again.

Mr. Smith gestured with the device at John. "Could I have that paper back first?"

"No. The device, if you would."

Mr. Smith looked insulted, but Sherlock was unaffected. "Mr. Smith, please don't make me constantly hold you at gunpoint for anything you happen to have on you, it's going to become very boring and very repetitive very quickly..."

The two held a ternse eye contact for a silent moment, then, reluctantly, the man handed over the device. Sherlock immediately set out examining it from every angle. Mr. Smith folded his arms over his chest and slumped slightly in his chair, adopting, if Sherlock were to actually believe the way he was acting, a pout.

"What is this?" the detective asked, not expecting an answer.

"A screwdriver," Mr. Smith replied, more that a little irate.

Sherlock's probing fingers paused and his eyes flickered back to their guest. A what? What kind of a lie was that? He scowled sharply. He did not appreciate the man's insolent humor.

"What?" the man challenged, shifting his arms to fold them even more tightly.

With thinly-pressed lips, Sherlock held the device from the end opposite the LED piece and flicked it sharply. Half of it slid apart in sections to elongate, four claws on the far end holding the LED in place opened, and the LED itself lit up brightly. The entire device emitted quiet electronic humming that rapidly climbed in pitch and intensity as Sherlock moved it around experimentally, and the lights in the flat flickered on without apparent cause and brightened in sync with the rising sound.

"Don't break it!" Mr. Smith, on instant alert as soon as Sherlock had figured out how to activate it, launched himself at the detective from the chair and grabbed for the whining device. He knocked it out of Sherlock's hand in his haste and immediately dove for it as the lights flickered back off and the device's pitch dropped. Sherlock rose quickly, knocking his own gun from the edge of the chair, and attempted to pull him away from it. The two fell to the ground in a small scuffle, wrestling for control over the now-silent device. They both successfully found strong two-handed grips on it and they both rose to their knees, trying to pull it comically from one another's grasp, shouting things angrily at one another and at John until the retired army medic's voice rang out over the both of them.

"Gentlemen!" he called in a surprisingly commanding tone. They both paused and look at him. "How many times am I going to have to do this?" John stood a few feet away from them, Sherlock's handgun pointed at Mr. Smith. His face was tired but militaristically hard again.

"Let it go," he said, his voice quiet once more as the flat fell silent.

Mr. Smith didn't release his grip. "I'm not giving up the sonic," he stated resolutely. "He almost blew apart the entire building's electrical system!" His gesture at Sherlock to emphasize his point cost him his advantage, however, and the detective ripped the device from his single-handed grip. Mr. Smith made a cursory grabby motion to get it back but Sherlock was already standing and inspecting it once again. He was not playing games and John still had the gun pointed at their guest.

"This is some sort of remote device..." he muttered to himself, resuming his chair as if the entire scuffle hadn't happened. Mr. Smith took a bit of prompting to get back into his, but soon complete order was restored. He sat down with an unplesant huff and straightened his bowtie and jacket. John decided to keep the gun at the ready should something like that happen again. Mr. Smith was only on the edge of his seat, leaning forward nervously, clearly worried about the fate of his curious trinket.

Sherlock had pulled out his Blackberry and was rapidly typing keywords into search bars, trusting his phone to tell him what Mr. Smith obviously would not. As he rotated the item once again to inspect for a serial number or some sort of manufacturer, Mr. Smith played with his hands in agitation, and licked his lips, wanting to say something but apparently unable to. Sherlock almost enjoyed finally getting to him after the way he'd been acting.

A call from Lestrade interrupted his searching though, and he took it immediately, rising from his chair.

"It's Scotland Yard, John, keep an eye on him," he said needlessly. He disappeared into the kitchen with the device. Mr. Smith half-rose as if to follow him, looking more anxious than ever, but John and his gun stepped between them and he fell back down in defeat.

The retired medic sighed. Of all the times for Lestrade to call them, it had to be now? Of course it was something big; if he had been asking for an update on a smaller case, he would have simply texted, or not even bothered, instead waiting on Sherlock to contact him with an answer.

Sherlock's voice was low in the other room, and the call was brief. Mr. Smith hardly had the time to attempt small talk with John before the detective had burst back into the room with a fresh energy and was taking long, brisk strides toward the door.

"Keep him here John!" he was saying as he pulled on his coat and scarf. "I'll send someone to hold him so you can join me later, but this is big!"

"What? Sherlock, I can't just hold an intruder here! What about the...the hypnosis or whatever?"

Sherlock paused at the door and turned around, tugging on gloves from his coat pocket. "Just...don't do anything he says," he commanded simply. "Don't give him the gun, don't take the gun off him. He can't hypnotize you into doing anything you don't want to, and he can only make you see things you don't expect. And he might not be able to do anything at all without this." He brandished the device he still had in one hand before tucking it into a coat pocket. "So I doubt you have much to worry about. Just expect everything, and you'll be fine!"

Mr. Smith stood sharply. "Hey-ey! You can't take the sonic with you!" He started toward the detective but John intercepted him and forced him back, retreating towards the door himself. "Give it back!" The man called, but Sherlock was already gone. He disappeared down the stairs at a thundering pace that would have tripped a lesser man.

"Sherlock, you can't do this!" John yelled after him. "Am I expected to shoot him if he tries to escape?"

Sherlock's voice floated back up to him. "He won't! You won't have to! He's harmless! Get him to help you clean up the kitchen or something! Join me as soon as you can!"

He slammed the front door closed with a bit too much enthusiasm behind him.