Chapter 1

"Oh, there's another act of vandalism." John was sitting comfortably in his chair with a newspaper. "The fifth already. They don't have a clue. The vandals seem to disappear within seconds, each time." He looked around at Sherlock.

Sherlock looked up from the terrier he was dissecting on the kitchen table. It had taken quite a lot of persuasion to get the go-ahead on this particular experiment. John had not willingly accepted that it was no different than working with any kind of raw meat intended for consumption.
He glanced over at John and then looked away to hide his smile as he answered: "Boring."

John sighed. "Yeah, as if that poor animal is so interesting. It's starting to smell."

Sherlock huffed. "It's perfectly fresh, and you did agree to this. If this is just a bid for more 'persuasion' it is a rather feeble attempt." This time he did not bother to hide his grin.

John smiled back. "Well, I wouldn't mind some more of your persuasion... But then of course that thing would lie there even longer."

Sherlock chuckled. "How about I finish here and then come over and persuade you thoroughly?"

"Hmm, looking forward," John grinned, looking back at his paper.

Sherlock smiled as he got back to work with increased speed and efficiency.

...

When he was done, Sherlock wrapped up the remains of the terrier and put them in the freezer. Then he took off his latex gloves and washed his hands. He went over and bent down to give John a soft kiss. "You needed more persuasion?" he asked.

"Yes. For letting you keep a dog in our freezer," John nodded, maintaining a serious expression while he pulled Sherlock into his lap.

Sherlock chuckled. "What will it take, I wonder..." He wrapped his arms around John's neck and kissed him passionately.

John hummed and laid his arms around Sherlock's back. "Oh, I could ask anything..."

"You could," Sherlock purred, nibbling on his ear. "How about I get us started and you let me know if anything occurs to you?" He let himself slide to the floor and settled between John's knees.

John chuckled and stroked Sherlock's jaw. "I like that plan. Certainly if you're about to start it from that position."

Sherlock smiled as he opened John's trousers. Then he nudged him to raise his hips so he could pull them down to his thighs along with his pants. He gave him a few strokes with his hand and then bent down, parting his lips to take him in his mouth.

John sighed and closed his eyes in bliss, but opened them again with a frown when he heard familiar footsteps on the stairs. Gently, he pushed Sherlock away.

"Oh dear, not again," Mycroft's annoyed voice sounded immediately when the door opened. "You two do realise that locking the door is the easiest security measure there is, and therefore an important one?"

Sherlock turned to glare at him. "And you do realise that it is considered common courtesy to knock before entering someone's home?" he asked.

Mycroft didn't look impressed. "That wouldn't change anything in your position. Get up, I've got a case for you."

John quickly pulled up his trousers and closed them, sighing. That could mean he'd have to wait quite a while.

Sherlock stood up. But instead of turning to face Mycroft, he bent down to give John a long lingering kiss.

John smiled and answered the kiss with a hand on Sherlock's neck, eventually using it to push him off slowly.

Mycroft rolled his eyes and turned to take a chair.

Finally Sherlock turned to him. "So what is it that was so important, that you had to grace us with your presence, brother dear?" he asked, settling on the arm of John's chair.

"Ifyou weren't too busy in the last few days," Mycroft cleared his throat, "you may have noticed that there were several acts of vandalism in the city, all performed in more or less the same way. There has been another one, today, this time not on any insignificant building, but on Westminster Abbey. For the sake of the public opinion, we would very much prefer this to stop."

Sherlock grinned, a bit sheepishly. "Westminster Abbey? What happened?"

John's eyes shifted to Sherlock for a moment and he suppressed an amused look.

Mycroft pulled up an eyebrow. "It looks a little like someone simply crashed into it with a small car, but no one has seen anything happen. That's the point. One moment when no one is looking, and suddenly a huge amount of damage is done."

Sherlock considered it for a moment. "Sounds mildly interesting," he admitted.

Mycroft allowed himself a mildly pleased look. "My car is waiting in front of the door. I could get you there immediately."

Sherlock considered for a moment. "Alright," he said. "I just have to go to the corner shop first." He looked at John. "Meet you by the car?" he asked, and then got to his feet and went to get his coat.

"Uhm, yeah," John answered, giving him a questioning look.

Sherlock winked at him and then nodded curtly at his brother. "Mycroft," he said and then he was out the door.

Mycroft shook his head. "Anything you still need to do, or can we go downstairs?" he asked John.

"No, I'm ready. I'll just get my jacket," John answered, getting up.

"Don't forget your keys," Mycroft said pointedly, and John gave him a look that said 'really?'.

...

Sherlock greeted them as he came strolling up the street, hands in his pockets and, quite unusually, chewing gum.

John frowned at him, but didn't say anything as long as Mycroft was still around.

"I'll leave you two to your task. I am expected elsewhere. Don't forget to report on your findings," Mycroft said, then nodded at John and got into the first of the two black cars.

Once they were settled in the back of the other car, Sherlock pressed the button that closed the partition between them and the driver. He glanced around and then took the gum from his mouth and used it to cover the lens of the small camera mounted over one of the doors, before he turned to John with a smile. "Where were we?" he asked.

For a moment, John glanced hesitantly in the direction of the driver and at the tinted windows, but then he answered Sherlock's gaze with a smirk. "You are unbelievable. The craziest man I ever met."

Sherlock chuckled as he unbuttoned John's jeans. "And that's a good thing, right?"

"Oh yes. I love it." John grinned and pulled him in for a hungry kiss.

Sherlock returned the kiss eagerly, as he pulled John's jeans and pants down. Then he leaned down and with a happy hum, finally took him in his mouth.

John let out a small moan and tangled his fingers in Sherlock's hair.

Sherlock knew their time was fairly short, so he went right to work. He sucked hard and began bobbing his head.

John placed a hand over his own mouth to muffle his groan, hoping that the driver wouldn't realise what was going on. "Fuck, Sherlock," he whispered.

Sherlock wrapped one hand around the base of John's cock and let it follow the movements of his head.

John tensed and tried to relax the hand in Sherlock's curls to keep himself from pulling. "I'm not going to last long like this," he said between clenched teeth.

Sherlock responded by sucking hard and then began moving faster.

John whimpered and had to bite his hand when his orgasm hit him.

Sherlock swallowed and then straightened up, a smug grin spreading across his face. Then he reached up, took his chewing gum off the camera and returned it to his mouth.

John giggled weakly. "Seriously. You just gave me a blowjob in a car and I don't even get a chance to touch you?"

Sherlock glanced out of the window. "We're here," he said, just as the car pulled up in front of Westminster Abbey.

"Oh, right." John tried to clear his mind a little and pulled his clothes straight, then leaned in for a quick kiss on Sherlock's jaw.

Sherlock smiled at him before getting out of the car. There was no need to ask for directions, as the damages were obvious enough.
Right next to one of the windows, there was a large hole in the wall, just large enough for a man to pass through. Stones and rubble covered the ground around it.

John pulled up his eyebrows. "Doesn't that look more like... you know, someone was making an extra door opening, rather than random vandalism?"

Sherlock nodded. "Yes. Except, why knock a hole in the wall right next to a window? Why not just break the glass?" As he approached the building, he got out his folding magnifier and was soon busy examining the edges of the hole as well as the rubble on the ground.
After half an hour he called John over. "This was not done by force," he said. "Look at the debris. If something had crashed into the wall, all the stones would have fallen away from the impact. But there are stones on both sides of the wall and even in the hole itself. It's like they just... collapsed. Like the mortar binding them just disappeared."
John frowned. "What do you think happened?"
Sherlock picked up a stone and examined it. "The mortar was dissolved," he said. "But not by a chemical agent. It's more as if it crumbled. As if it was shaken apart." He turned the stone over in his hand. "By... sound waves...?" He dropped the stone and began pacing. "But that is not possible. No technology exists that would be capable of that."
Suddenly he stopped and turned to look at the stones on the ground. "I need your help, John," he said as he rushed over and picked two of them up.

John was immediately by his side and kneeled down.

"Help me gather the stones," Sherlock said. He picked up a few more, carried them a little distance and placed them on the ground. "We have to piece them together," he explained. "See if anything is missing. This was not done to gain entrance, but to get at the stones themselves."

John sighed and started on the almost impossible puzzle the stones were. "Why would anyone take the stones? Even if they're valuable, everyone will know the sellers are the vandals. Is this some strange collecting mania?"

"Let's start with figuring out what is missing before we try speculating on why," Sherlock answered with a smile.

"Sorry, theorising without the facts again," John chuckled, putting a couple of stones in place.

Sherlock grinned. This was quite a different puzzle from what he was used to. But definitely challenging.

Soon, the challenge was mostly replaced by frustration, at least to John. Some bits just didn't seem to fit, and although the stones hadn't been so heavy at the start, his left shoulder was beginning to hurt. Of course he didn't say anything and went on, relieved as he saw that they were making progress.

Finally Sherlock stepped back. He pointed at the hole in the middle of the stone-puzzle. "There," he said. He smiled at John. "Why don't you go find us some coffee and I'll see what I can learn from this."

John nodded. "Alright. Don't wreck the rest of the building while I'm gone."

Sherlock chuckled. "I'll try not to." He went over to the two police men posted to keep an eye on the site and demanded to be supplied with lots of paper and pencils.

...

"Did the stones reveal their secrets?" John asked when he was back, handing Sherlock his coffee.

Sherlock nodded and held up several rough sketches covered in scribbled notes and numbers.
"The stone was slightly larger than any of the others, but otherwise it seemed fairly ordinary. At least that's all I can deduce from the evidence at hand."

John looked thoughtfully at the sketches. "Should we go to the other damaged buildings and see if there's any similarity?"

"Brilliant suggestion, John." Sherlock grinned. "Good thing Mycroft's car is still here." He took a fresh piece of gum and started chewing.

With some difficulty, John managed not to stare at his mouth and went to the car.

Sherlock got in and leaned forward to talk to the driver. "We need to visit the other sites where this vandalism has taken place. In reverse chronological order." At a look from the driver, he sighed dramatically. "The newest one first, the oldest one last." Then he leaned back and raised the partition.

John slowly looked at him. "Do you want...?"

Sherlock raised an eyebrow. "Do I want what?"

John waved in the direction of Sherlock's crotch. "You've got chewing gum."

"Indeed I do," he chuckled as he took the gum from his mouth and once more covered the lens. Then he looked at John expectantly.

John smirked up at him and sat closer to stroke his neck, while he started opening Sherlock's trousers with his other hand. "Crazy," he repeated, pressing a kiss on his neck before he bent down to his lap.