I do apologise for being so long with this. I have put my OC in and I hope you enjoy her because her name is the puzzle. The name introduced will be changed in future chapters because there are some things going on. Dark! Marty will be introduced and there may be severe character death. Enjoy the third and final instalment of the Dark! Marty Series. Thanks to all my supporters who have supported me during the previous BTTF stories. There will be songfics for random characters to including the OC that stars in here. Anyway, enough of my yabbering - enjoy!

Previously

October 27th 1985

The boy was clambering into the dead car and forced the DeLorean to start from an ominous power source.

"Where I'm going, I won't need gas or garbage to get this scrapheap moving…" An evil snigger escaped the Mcfly's lips and he lifted his head up to reveal sinister glowing orbs.

He revved the vehicle and crashed through the garage door – dissipating in a flash as he vanished to an unknown place and time.

Now the Doc had already formulated a plan. Sitting in the garage – undercover – was another DeLorean – a new DeLorean. It had Mr. Fusion attached to it and it was very able to fly.

As the doctor inputted the time needed to save Marty from his shadows he murmured to himself, with a few dribbles of salty tears.

"Marty, my boy. I will rescue you. No matter what it takes. You have my word."

And with that comment the new time machine hovered above the garage's floor before flying after the original into 2015.

October 21st 2015

The Doc yelled in disbelief at the hell that was 2015 as he dodged a fiery meteor from hitting the car.

The Hill Valley of the future was ablaze. Screams echoed from fleeing citizens as a maniacal being cackled spreading destruction. Children were reeling in fright from a mad figure in the centre in front of the clock tower, trying in futility to find their mothers.

Not far from the clock tower, stood an entire graveyard – full of hoverboards and fried skeletons left unburied – left to die without dignity.

Emmett gawped in sorrow as he landed the DeLorean and he scanned the scorching area for his possessed best friend.

Instead he found another teenager.

She didn't look like she belonged in the future. The blood stained clothing didn't look right at all. Tears of blood streaked from both corners of thin, chapped lips and her eyes shone with hope. Red hair burnt at the ends by some of the flames licking about the hellish place and Doc smiled at the fact she was reversing towards him.

She was trying to find a way to escape – whoever this girl was she was on the verge of giving up and trying to defend the vulnerable old man.

"What the hell are you doing here, you crazy old man?!" The teen screamed as she slowly backed towards Doc.

"Same reason you're probably here, young lady!" Replied Emmett, "I'm trying to help my friend and return back to 1985 with him where we belong. Thanks to that infernal time machine he got infected by something from the original timeline and now an alternate timeline has been created."

The girl sighed as soon as she was side by side with Doctor Brown. She extended her arm to take Emmett's hand and shake it.

"Names Timella Trever. But you can call me Ella – it's easier for everyone then. I have my own method for travelling through time. Just think about what location I want to be at, then the time – then boom! I'm there. 1985 huh? I'm from 1991, so go figure eh?"

Doc laughed gently as Ella got excitedly carried away with herself.

"Timella Trever. Now why does that sound familiar? Doctor Emmett Brown, inventor of time travel – in a DeLorean." He smirked, lifting an eyebrow to the girl.

It was Timella's time to giggle now.

"I thought you might understand the giggle of my name – had to change it ever since the unchangeable incident. He does have a bad habit of letting himself be known."

A loud whining noise could be heard and the duo looked up to see that a vehicle was lowering itself down close to them.

Marty hovered down in the old DeLorean. His glowing eyes looked utterly demonic and full of bloodlust as well as rage.

"Oh, how quaint, Timella's arrived… The legendary traveller of time. The one who's made sure she has removed herself from history and prevented herself from being known. Not often you stop to make new friends. Pathetic excuse for a human." Snorted the possessed teen.

"The Darkness… You can't carry on like this. I offered you the chance to reform and stop pushing guilt onto Marty Mcfly. Now I make this offer. Stop this war on the light or perish. You feed on chaos, and you want to create turmoil with this teenager. Well I'm not gonna let that happen anytime soon, you want pandemonium? Come and fight me, you won't win." Ella reasoned sternly.

"Great Scott! Darkness?"

The Darkness, the possessor of Marty hissed and tried to lash out at the female. She disappeared in an instant blue light and appeared behind the dark teenager to knock the body snatcher to the floor.

He gasped in pain.

"Get to your vehicle, Doc. I'll bring him back home to Hill Valley 1985 – okay? And I'll promise to explain everything once we're back." Ella pleaded.

Doctor Emmett Brown quickly obliged as the female teen heaved Marty's limp, unconscious body over her shoulder.

"Don't worry about time fuel, I sorted it out. Travelled back in time before knocking your friend out cold and refuelled Mr Fusion…"

"Thank you, Timella." The Doc thanked gratefully.

The engines of the DeLorean whined and growled like a cougar as it took off back to 1985. Ella hauled Marty into the old DeLorean and drove after Doctor Brown to the Hill Valley from the past.

Sorry this first chapter was quite short, but it did take a little time to think about - and I have been on holiday. Hope you enjoyed and please leave a review!