Author's note: I was asked for a summary. I know my stories can be confusing, so here it is: Sherlock and John were thrown into a parallel universe when they were investigating a man named Trevelyan, who wants to use travels between dimension to control his own. Changing things in the parallel universe - like, for example, causing a chain of events that wouldn't have taken place by changing someone's mind, or murdering someone who was supposed to live - makes it possible to change things in one's own universe. However, one has to go to a parallel universe and can only change the reality of one's own. Trevelyan murdered a scientist and brought back Moriarty in his universe - he survived the Fall and has been controlled by Trevelyan ever since, which he resents.

Trevelyan's goal is to control Britain and make sure that everything is run the way he imagines it - through Science.

Sherlock and John met their own counterparts - John is a consulting detective, Sherlock is called Bill and is his best friend. Lestrade is a member of his homeless network, and Moriarty is Jim from IT, who helps them gain information. They found out that there is a consulting criminal in this world as well, who is working with Trevelyan to be able to control it. It's Mrs. Hudson.

They are on their way to another scientist, who can hopefully help them find Trevelyan, while Mycroft and Greg found Moriarty in their world and are in possession of the machine that could allow them to return home; they have to be near Trevelyan and his sensor to allow that to happen, though.

I just confused you even more, didn't I.

They returned to the dining room and stared at the device.

Greg's hands were clenched into fists. If they brought back Trevelyan, there was no reason to think that he would help them to find Sherlock and John. He wondered if Moriarty had known – if he had taken pleasure in the fact that they were looking for a machine that couldn't do what they wanted, needed it to do – but it didn't matter.

There was only one thing they could do now.

He took a deep breath.

"We have to trust Sherlock."

Sherlock would find Trevelyan; Greg was sure of it.

Mycroft nodded. He looked tired and worn out; he must have been fighting the memories while he was alone. Greg hadn't had a problem, in the living room with Moriarty, because he had seen what had changed.

"We'll give him two more hours" Mycroft decided.

Moriarty stayed silent as they settled down to wait.

Sherlock went back to Gregson's office to find that John had had a more difficult task at convincing the DI than he had with Dimmock, but that three cars would be sent out.

"It should give us an hour, at least" John said as they returned to the others.

"Garrideb, then" Sherlock began. "Jim?"

The other man happily told them the address again, along with the other information he had been able to find. Looking at him grin, his similarity with Moriarty was harder to ignore, and Sherlock nodded so his voice wouldn't betray him.

He was glad John was standing behind Jim; the doctor obviously found it difficult to hide his feelings.

John listened to Jim and wished he could punch him. It was completely irrational, not to mention unfair – and he had done it before. But this happy tone... It reminded him too much of waking up and being decked out in Semtex and a consulting criminal who'd cheerfully explained what he had to do.

Bill nudged him and John looked at him to find understanding in his eyes, if accompanied by weariness because Jim was his friend and he didn't want him to be hit again.

John smiled, although it was clear by Bill's face that it was a rather weak smile, and shook his head.

He had almost forgotten about Mike until he made a step forward and studied them as well as Jim; he was frowning, and John was certain that once this was over he would demand an explanation from his brother.

Garrideb didn't live that far away, if in a gloomy-looking house at the end of the street.

"Do you propose we just walk in there?" Mike asked. The silence of the others was answer enough, and he began "And what if – "

"He has done research into parallel universes" Sherlock said. "He will know what is going on. Trevelyan may already have contacted him".

"And if he didn't?"

"Then he will soon."

"Soon enough for her to find us" he grumbled, but didn't say anything else as they rang the doorbell.

Greg left them to watch from afar, claiming that he would keep watch; Sherlock knew that his homeless network was more than capable of staying invisible and trusted that he would do so. This led to a quick discussion, while footsteps could be heard approaching the door, but finally Bill convinced his brother and Jim to wait with Greg. It was for the best. A man who never left his home was certainly not used to much company.

Eventually Garrideb opened the door. He was an elderly man with a friendly twinkle in his eyes, not someone one would have imagined to be a scientist. Then again, John wouldn't have thought someone like Trevelyan would commit murder.

He gave them a shrewd look.

Trevelyan had been in contact. There was no doubt in Sherlock's mind. Now it remained to be seen on which side Garrideb stood.

"Fascinating" he said, pushing his glasses up his nose. "I have studied parallel dimensions for years, but to finally see the proof – "

"Could we step in, please?" John interrupted him.

Garrideb blinked.

"Of course."

He stepped aside and let them enter.

They followed him into a living room that was full of small statues and instruments and books and messier than 221B had ever been, and Sherlock decided to remind John of it when the doctor began to complain again.

"So. You are from a parallel universe" Garrideb said, sitting down on the only chair. He didn't offer them a seat, but it would have been difficult to locate one anyway.

"Yes" Sherlock said.

Garrideb hummed, but didn't reply.

"We think" John Watson said, "that Trevelyan might try to contact you."

"If you are anything like your reputation suggests, Mr. Watson, you will know that he already did" the other man answered. In fact, he is upstairs."

All of them looked up. Sherlock could feel excitement coursing through his veins.

"He thinks that I believe him a genius, and that I will help him".

"You won't".

It was a statement. Sherlock had seen it in his eyes, in the way he had sat down, the relief in his shoulders. He was glad they were here, and not because he wanted to destroy them.

"You are right."

"But why – " the doctor began, but Bill interrupted him, "He doesn't approve."

Garrideb nodded.

"I am a scientist. I love theories, I love speculating. I love finding proof. But Trevelyan... He took it and he used it, used science for his own personal motives, and I don't like that."

He might have told him that not only had Trevelyan used science for personal gain, but that he had also killed for it, but Sherlock doubted that this would have the same effect.

He looked up again, going through their options.

Two hours dragged by. It was difficult to keep remembering, and Mycroft's ashen face told him that he had the same problems. Moriarty was cheerful, but quiet, and Greg wondered if he only wanted to make them think he had a trick up his sleeve or if that was the truth.

"Does he want you to call him down?" Sherlock asked.

"When all's dealt with, yes".

"You mean – " John began, but Garrideb answered, "when I've sent you away, of course. I'm not a barbarian".

"Give the signal".

Sherlock said it quickly; he heard John and Bill already moving to both sides of the door, and John came to stand beside him. There was no point in hiding. They would have to talk to Trevelyan, find out how to return home.

Garrideb took a broom and knocked on the door.

They heard Trevelyan walk down the stairs. He entered, and John dragged him inside and closed the door, standing in front of it. Trevelyan looked at him, shook his head and turned around to face Sherlock and John.

"I should have know. I will never find someone who understands me".

John found it difficult to pity him.

They drew their guns. Garrideb withdrew in a corner and picked up a book, unconcerned to what was happening.

"Would you really kill me?" Trevelyan asked, then answered himself. "Of course not. You want to go home. You want to destroy everything".

"If you mean that we want to make sure nothing like this happens again, you are right" Sherlock responded.

"Then I'll have to prevent you from doing so" Trevelyan said softly.

"Even if you managed to kill one of us – "

"I know" Trevelyan said. "The others would get me. And that's the problem. You simply – can't".

Sherlock tried to move a step closer, but the other man immediately drew a gun.

"It's a shame; but without me you can't return. You don't know how to activate the sensor if someone doesn't press the button in our universe. And it's unlikely that someone should. Therefore, you need me. And I am sure you could get me to talk".

"Yes" Sherlock said, his voice holding a deadly promise.

Trevelyan sighed.

"She will take care of you" he said confidently. There's one regret, though – I really wish I could have seen the fruits of my work, but many people haven't."

What he wanted to do flashed across Sherlock's mind in an instant, but as he was stepping forward, Trevelyan pulled the trigger.

His body fell on the carpet.

They stepped towards him in the silence, all of them except Garrideb, who was happy to stay with his book.

They stared at him, for a few seconds unable to comprehend what had happened.

"What now?" John asked. "We don't know how it works – "

There was finality in his voice, like he was already accepting that they would never return home, but Sherlock wouldn't allow that. There had to be a way.

Sherlock looked at the sensor.

"Two hours" Moriarty remarked. "Time to try, don't you think, Big brother?"

Mycroft didn't answer him. He looked at Greg. The DI nodded.

"Sherlock found him" he said. While he wasn't sure and said it to convince himself as well the British Government, he couldn't help but feel that his friend had indeed traced Trevelyan. He was Sherlock Holmes, and he had John at his side. He could do anything.

Mycroft stared at the machine before he reached out, his hand trembling. Greg desperately hoped that they would succeed; the strain was beginning to take its toll; he felt that his thoughts were getting more confused by the minute.

Mycroft pressed a button.

At this moment, it started to blink.