This is inspired by The Butterfly Effect, and is a slight cross-over (No characters from TBE have been used)
It doesn't matter if you haven't seen The Butterfly Effect (There are hardly any spoilers for the film) but if you haven't I recommend you watch it, a brilliant film!

Enjoy!

Change one thing

Change one thing, change everything.

Such minor changes, such huge consequences.
The end is only the beginning
(The Butterfly Effect)

"Oh my god!" A voice shrieked as I opened my eyes dizzily, I looked around, I was in the Tardis, two people were running towards me. I couldn't see them properly, I screwed my eyes up at the pain that cracked through my skull "It's alright, I've got you!" The voice cooed grabbing at my arm "What's happening to him?" I opened my eyes and took a deep breath, I saw Martha starring back at me horror struck then saw Captain Jack Harkness stood right behind her looking over me with the same worried expression on his face.

"What happened?" Jack asked calmly as Martha dashed off, to retrieve the medical kit I expect.

"Oh god…No…What did I do?" I yell in a panic, more pain seeps through my neck, I twist it making it crack loudly, Martha shudders and cringes as she returns.

"Doctor, what were you doing?" Jack asked, I starred at him. He frowned back at me "What?" He asked gently.

"You shouldn't be here…" I mumbled biting my bottom lip still with locked eyes on Jack "I can't believe I did that…" I stare at the floor babbling away "Why did I do that, why! My people practically invented time travel and the rulebook to go with it…I had to go and break those rules didn't I? No travelling along a personal time line. Even though it was technically my timeline I still changed your life Jack…God I'm such an idiot! I have to go back…Where's the journal?" I glanced up noticing Jack had hold of it, I reached up but felt that familiar crack of pain run down my arm again. Time travel without a ship…Bad.

"What…Did…You…Do?" Jack tried again.

"I read an entry from that journal, I wrote it a while ago. Still do in fact and then suddenly I was there again, as my previous regeneration and I changed time…"

"But how?"

"I went back for you." Jack blinked at me a couple of times "Yes…I left you behind, then went back in time through the memory and changed everything. That's why I must go back!"

"And leave me behind? No way." Jack pocketed the book and strode away.

"Jack! I need it!" I begged trying to get up only to be thrown back down from pain "Don't you dare read it!" I bellowed after him but he had gone.

I got the journal back, stole it in fact, well technically it isn't stealing seeing as it is my own! I pull it out of my pin stripped blazer pocket, haven't worn this jacket in a while, I pull something out with it. A letter sitting neatly in its opened envelope with 'Doctor' addressed on the front. I remember who it is from instantly, Madame de Pompadour. I search frantically for the page in the journal about her, I remember her now, a beautiful young lady who was being harassed by clockwork droids!

"Jeanne-Antoinette Poisson. I snogged her. Yep! I snogged Madame De Pompadour! Beat that…A wonderful short time I spent with her, though I regret never getting to show her the stars…" The room started to flicker and shake and before I knew it, and before I could stop myself, I was back in 18th century France in Reinette's room.

"Doctor…Are you alright? You seem…Lost?"

"Uh…Right, 18th century France, looking at the stars…Wine in hand…Reinette…Ah! Sorry, bit lost yes."

"You are such a strange man, strange but wonderful! And yet, you knew that saving my life would mean you becoming trapped here forever. Didn't you?"

"Oh no worries…Loose connection."

"Pardon?"

"I mean, yes." I must remember to not give away events before they happen!

"You see the fireplace over there?" I nod gently, knowing what is to come "I had it moved piece-by-piece…That is my childhood fireplace, I had it moved in hope you would come back."

"That means…The bond with the ship has been severed meaning it should be an undamaged portal, meaning I can get back!" I rush to the fireplace and tap a finger on it to find the loose connection again "Aha!" I sonic it with my screwdriver "But first, Reinette, you want to see the stars…Pick a star, any star." I rush to the window and drag her along by the hand "Any one!" She gazes out, I watch her gleefully, this time I will allow her to see the stars.

"That one." She points and I nod.

"Now come with me." I take her to the fireplace and together we go through the time window and end up near the Tardis, I invite her in and she marvels at the sheer size of the console room compared to outside the box. As I set the co-ordinates everything flashes white and I find myself face down in the carpet of the Library inside the Tardis. I pull my face up and sigh at the red stain in the material; nothing will get that out!

I screw my eyes up and stretch my neck, no horrible cracking sounds, yet. I sit up and clutch a hand to my forehead, now the pain is coming…I feel it surge from the pit of my stomach, up my back, along my arms and up my neck into my head, cracking bones as it moves upwards, I open my mouth wide to scream but nothing comes out. I feel a warm liquid trickle down past my lip, then it all stops and I take a couple of deep breaths. I wipe the blood away and stand up shakily.

"Doctor, are you alright?" I hear a familiar and long lost voice ask, I turn and face her, Reinette, as beautiful as ever, but dressed in twenty first-century clothing.

"Reinette?" I stutter swiping away another stream of blood that has decided to come out of my nose.

"You are bleeding." She rushes towards me and simply stares at the red liquid gushing from my nose.

"Uh, yes, so I am." I press a sleeve over my nostrils to stop the bleeding "Where is Martha?"

"Who?"

"Martha, Martha Jones?" Reinette looks at me puzzled "Oh no…I never went for her did I? I never invited her to join me because you are here now…Oh god what have I done now? Is Jack on board?"

"Yes, in the console room." I pick the journal up off the floor, noticing the letter from Reinette has now disappeared and hurry off to find the Captain.

"Doctor, I don't know who Martha Jones is! Stop asking me that."

"But Jack…She's real, oh my god why did I do it! Why!" I slam a hand against the back of my head, I'm such an idiot, I should know the rules off by heart about time travel but still I choose to ignore them "I need to fix this, I need to fix it all." I pull out the journal and find a new entry, written a good time ago, about Reinette "I took her to see the stars, she marvelled at them all…" The room flickers and suddenly I'm standing at the door to the Tardis next to Reinette.

"Why I'd love to travel with you." She smiles at me, her face so bright with excitement, I'm a bit too late, I've already asked her.

"Uh…No…Sorry, I must take you back Reinette."

"But why?"

"I can't take you out of your timeline, you are supposed to marry…If that never happens, if you just disappear I'll upset the future, well past, greatly. I must take you home, I'm sorry." I walk forwards then trip clumsily and land face first into the console, thankfully I didn't knock any buttons.

"I've got you." Jack calls grabbing my middle and pulling me to my feet "Oh god, Martha!" He calls; I smile dumbly to myself as I hang limply in Jack's arms. I have no energy to stand on my own two feet; I must stop this time travelling "Martha!" He shouts again clearly in a panic, I hear footsteps followed by a 'What do you want now?' then a 'Oh god…Medical kit!'.

Jack lays me down on the floor of the console room, I smile lazily back at him.

"Where is Reinette?"

"Who?"

"Good." I smile to myself knowing she was sent back home safely.

"You've been acting weird lately Doctor…" He started.

"Yup." I replied not caring, as Martha pressed a soft wipe to my nose. This time travelling without a pod and changing history was extremely painful on the body! Even though I had re-wrote part of Jack and Martha's time line in getting the Captain back, it still felt good to have him here. I don't regret doing that, I have Jack back and maybe if I can succeed in that, I can succeed in other things too.