Ok, this is my first story so go easy on me! Disclaimer: I do not own any of the characters from Doctor Who and Buffy th Vampire Slayer. All credit goes to Russel T Davies and Joss Whedon. If you haven't watched the last episode of season 5 of Buffy this first chapter won't make sense. But the general idea is that ALL the diemesional portals to ALL the other worlds has opened.

The Timelord and The Slayer

Death and Life

"It has to have the blood"

Buffy knew that Dawn was right. Glory had opened the portals to other dimesions using Dawn's blood and to close the portals Dawn's blood would have to stop flowing. Dawn would have to die. That was the moment Buffy realised. All of the events of the past year was finally making sense.

"It always got to be blood"

"It's Summers blood, it's just like mine"

"She's me, the monks made her out of me"

"Death is your gift" "Death.." "Is your gift"

She had figured it out. Dawn wasn't really her sister, she was a mystical key key that could open the walls between worlds with her blood. But a hell god who was banished from her own world wanted to use her blood to get back. But ALL the portals would open so anything else could get though to there world and meant the end of ALL worlds. So to stop the hell god from using the key three monks made the key human and put it in the care of the slayer - Buffy. And the only way to stop the end of the world was to kill Dawn. She could never do that, but know she didn't have to. The monks made Dawn her sister. That means that Dawn's blood runs in Buffy's veins. If she sacrificed herself the world would be saved. She decided she was going to do it. Dawn knew what she was going to do.

"Buffy, no" she pleaded.

"Dawnie, I have too"

"NO"

"Dawn, listen to me, there isn't a lot of time left, listen, I love you, I will always love you, but this is the work that I have to do. Tell Giles, tell Giles I figured it out and I will be ok. Give my love to my friends, you have to take care of them now, you have to take care of each other. You have to be strong. Dawn the hardest thing in this world, is to live in it. Be brave, live. For me."

Buffy leaned over and kissed Dawn on the cheek. She tasted the tears that were flowing down Dawn's face. She slowly backed away from Dawn one step at a time before she turned around and ran. She swan-dived off the edge of the tower accepting her fate. She entered the portal into other dimensions. Buffy was gone and the portal, closed. Dawn ran a fast as she could down to the bottom of the tower. She looked around she saw Giles, Tara, Willow, Anya, Xander and Spike but her sister's body was no where to be found. Giles saw Dawn and ran over to her.

"Dawn, Dawn are you alright?"

Dawn could barely speak barely think she had just enough strength to nod her head once or twice.

"What happened, where's Buffy?"

The name of her sister made Dawn cry even more tears.

"She's gone, she jumped into the portal and saved us .."

Dawn could not finish the sentence by now all of the scoobies and Spike had gathered around her and Giles and she just couldn't take it. She fell to floor in a puddle of tear mourning for her dead sister.

Buffy opened her eyes she had no idea where she was. Wherever it was it was huge.

"WHAT?"

Buffy gasped to the sound of a voice she didn't know. She turned around to find a man staring at her she let out a little scream. The strange man was dressed in a three pieced stripy suit. He had brown hair that was spiked up in loads of different places. He had a pair of Converse All-Star trainers on. He wasn't that bad looking.

"Who are you?" Buffy asked.

The Doctor stared back at Buffy he didn't know what to think. He had just said goodbye to Donna after she left the Tardis. And now there was this blonde women standing in the Tardis. She was wearing a white jumper and a pair of long flowy beige trousers. With high-heeled boots. She looked like she had just been in the battle of the century. Still she wasn't the bad looking.

"I mean, well I'm the Doc .. I mean ... WHAT?"

There we have it my first chapter! Please R&R. Comments good and bad appreciated. Next chapter will be posted soon.