Picard was sitting in his quarters when the door chimed.
"Come", he said, putting the book down. The door opened and Rosalie stepped inside.
"I hope I do not disturb you, Captain", she said.
"No, of course not", he answered and rose. "Come inside."
He walked over to the replicator.
"Do you wish to have something to drink?" he asked.
"How about the same that you drink?" she answered, nodding at his own cup and then smiling slightly at him. "Tea, Earl Grey, hot."
The replicator immediately responded to her order, leaving Picard slightly off balance in surprise. He soon composed himself, however, and carried the cup over to the table, placing it in front of her.
"You're still reading Shakespeare", she noted, nodding at the book. "Which play?"
"How come you know these things about me?" he asked. She put her cup down.
"Do you remember how I questioned Doctor Crusher if I was dreaming?" she asked.
"Yes, of course."
"Well, the reason for that was that I am not from here", Rosalie explained. "I'm not from this planet, not from the Federation… not from the same universe, to tell the truth, but one parallel to yours."
"What are you saying?" Picard asked, leaning forward.
"I come from Earth", Rosalie answered. "I was born 1991 and I am twenty years old. I have just started to attend University and moved into my own apartment."
"That's impossible", Picard said.
"If it was I would not be here", Rosalie remarked. "Have you analyzed the fragments of the explosion?"
"Commander Data is working on it right now…"
"I think that there might be a chemical reaction involved", Rosalie interrupted. "Back home the scientists are talking about a chemical substance known as Nivocarton; it's said that it could blast a hole in the universe."
"Do you believe that this substance was involved in the explosion?" Picard asked.
"It is a possibility, or perhaps they have another one that works the same way", Rosalie answered. "But if it was used it was used knowingly. From the published papers I've read it's really hard to make and even harder to use. One in two thousand works as planned."
"Do you know the chemicals involved in this?" Picard asked.
"I don't have them memorized", Rosalie admitted.
"But if you saw the combination of chemicals written in front of you, do you think that you would be able to recognize it?"
"It's possible."
Picard tapped his combadge.
"Commander Data, report."
"It seems that a chemical reaction was involved in the explosion, Captain", the android answered. "I do not recognize the combination, however…"
"Stay where you are, Mr Data", Picard interrupted. "I'm on my way."
He nodded at Rosalie and together they walked out of his quarters.
"That's Nivocarton, alright", Rosalie said after having studied the chemicals listed on the screen. "It's the same list as the one they had in the papers."
"Are you sure?" Picard asked. "There are a lot of chemicals."
"Look at the letters for each chemical substance", Rosalie answered and pointed. "N for nitrogen, I for iodine, V for vanadium, O for oxygen, C for carbon, Ar for argon, Th for thorium and NO for nitric oxide. Combine those letters and you get Nivocarthno, which the scientists back home changed so that it was instead called Nivocarton."
"It is a very unusual combination, Captain", Data said. "If this combination was to explode like it did down on Feltan III the combination would have to be kept under perfect conditions, but it would have a lot more force than the explosion we witnessed."
"How strong do you predict that such an explosion would be?"
"Fifty-nine percent stronger than an explosion in our antimatter-chamber", Data answered. Picard looked at Rosalie for a moment and she met his gaze.
"Mr Data, would such an explosion have the power to rip a hole in the universe?"
Data tilted his head slightly.
"It could be possible, Captain", he said after a while.
"That was what happened", Rosalie said. "But why are they trying to do it?"
Before anyone was able to answer the ship started to shake violently. The alarm blazed red and the siren yelled.
"Another explosion, Captain!" Commander Riker yelled from his position. "But this time it's a hell lot more powerful!"
The shaking slowly came to a stop and Picard helped Rosalie rise from the floor.
"Damage report!"
"Casualties found on decks four, nine and twelve", the female ensign answered. "Feltan III reports no casualties except for the bomber."
"How is that possible?" Riker asked. "If the explosion was so big that it affected us how can the planet and its inhabitants be unharmed?"
"Oh my God", Rosalie said and stared out through the window. "They did not just do that…"
Everyone followed her gaze and spotted the two blue boxes spinning between them and the yellow planet below.
"Is it just me or are there two boxes?" Rosalie asked after a while.
"There shouldn't even be one!" Riker exclaimed.
"Agreed, but that means… they opened up holes to two different universes at once."
"What are they?" Picard asked.
"Space-ships", Rosalie answered.
"What?" Riker asked.
"They are a lot bigger on the inside", Rosalie explained. "Captain, I suggest we hail them."
Picard nodded.
"Open a channel", he said. The ensign obeyed.
"Channel open, sir."
"This is Captain Jean-Luc Picard of the Federation starship USS Enterprise. Do you read me?"
There was no response and no change.
"I do not read any life signs onboard", Data said. "But the shields are very powerful; I am unable to get a clear scan."
"Doctor?" Rosalie said. "Doctor, do you read me?"
Everyone looked at her in surprise, then once again awaited a response.
"Doctor?" Rosalie repeated. "I know you're in there; the TARDIS would not let you die while onboard. Are you hurt?"
"Not in the least", came the sudden response. "Hello, I'm the Doctor!"
"What?" said another voice. "How can… what?"
"Doctor, can you get the TARDIS onboard the Enterprise?" Rosalie asked. "Aim for the Bridge and we'll clear away."
"Since when are you allowed to…"
"Since the moment the Doctor answered me and not Captain Picard", Rosalie interrupted Riker. "He believes I know him, therefore he believes that he is here because of me, meaning that at the moment he trusts me."
"Lower the shields and clear away", Picard ordered and pulled the girl with him back to the wall. The others on the Bridge followed and suddenly a wheezing noise was heard. Wind blew in their faces and slowly the two blue boxes materialized in the room, one by the turbolift and one by the door leading to the Captain's ready-room. The wheezing sound stopped and the doors of the two boxes creaked open, revealing two young men. The one by the turbolift had messy, brown hair and was wearing sneakers and a blue suit beneath a long, brown coat. The other one had black hair and blue trousers, a shirt and a tweed-jacket, which he matched with a bowtie. For a while the two of them stared at each other.
"Was that how I looked?" the one with the bowtie asked after a while.
"Oi, I checked myself in the mirror after defeating the Sycorax. If you're me you got to remember that."
"Oh yes, that's right."
"You're wearing a bowtie?" the man with the suit asked and walked down the ramp.
"Yeah, I do. Bowties are…"
"Brilliant?"
"Cool."
They grinned at each other.
"Right, onto these more pressing matters", the one with the bowtie said.
"I was hailed by a Captain Jean-Luc Picard… ah, there you are, allons-y", the other one continued and grinned when he spotted the Captain.
"Now, that should not have been possible if…"
"The void has not been damaged so…"
"Is that what has happened?" the one with the bowtie finished.
"You're worse than Fred and George Weasley", Rosalie said and crossed her arms over her chest.
"And you've got to be the girl who knew me… or, well, us", the one with the suit said with another grin.
"Hold on", the other one said and pulled out a small metallic handle. He pressed a button and it started to whirr with a green light shining on its end.
"Void-stuff", they both said after a while.
"That's a very nice sonic, how do I get that?" the one with the suit then asked.
"Spoilers", the other one said. "Anyway, how come you've got void-stuff all over you but the rest of the crew hasn't?"
"I'm not a member of this crew", Rosalie answered.
"Then why were you…" the one with the bowtie begun.
"Oh, that is brilliant!" the one with the suit interrupted. "Parallel worlds; you were brought here as well."
"I was going to say that."
"Alright, could you two…" Rosalie begun.
"Doctor?"
"Yes", the two men said and turned towards the box that the one with the bowtie had stepped out of. A red-haired woman and a man with reddish hair stared at the scene.
"Wow that is weird", the woman said.
"Amy, Rory, get out here", the one with the bowtie said. "Now, first, meet my past self."
"Hello, I'm the Doctor", the one with the suit said. "And here's the crew of the USS Enterprise and… what was your name?"
"Rosalie", Rosalie answered. "And I don't know about you guys, but having two people called the Doctor to keep up with is making my head hurt."
"Hold on, do you know him?" Amy asked.
"Indirectly", Rosalie answered.
"Parallel universes", the two Doctors answered at once.
"Like you said; weird", Rory said.
"Captain, our scanners have detected the preparations of another explosion", Data said.