Starts at the end of Putting the Pieces Back Together, Part 4.
...
'Where the hell is the bastard?' Buffy wondered in near maddening frustration as she entered her neighborhood.
And as if fate suddenly granted her a wish, she spotted him.
He was lurking outside her apartment, not 100 feet away from her.
And he had her sister.
'Dawn!' Her mind screamed, knowing Angelus was baiting her, waiting until she came home, just so he could kill her only family right in front of her eyes.
With a speed and stealth even she had thought impossible for her to achieve, she shot over the distance, stake aimed for his dead heart.
...
"Angel? I thought...we all thought you were dead." Dawn gasped in surprise when she saw the MIA vampire materialize out of the darkness.
"Been hearing that a lot Dawn." He said, forcing a smile to his lips.
"Does...does Buffy know you're alive?" She asked.
"She does, in fact, I came to find her...is she here?"
"No, she went patrolling a few hours ago...she should be back any minute now." Dawn said as they stood together outside the apartment.
"Good, I really need to talk to...her." He wetly gurgled the last word before collapsing.
"Angel!?" Dawn asked frightened when he suddenly dropped.
Buffy appeared behind where Angel had just been standing, a bloody stake in her hand.
"Dawn, get away from it." Buffy yelled as she practically dragged Dawn back.
"Buffy! What did you do!" the young woman cried out when she realized Buffy had staked him.
"He's soulless." She defended, expecting to see Angelus's body dust any second now.
Any second.
It wasn't dusting.
"What? Why?" Buffy asked, looking down at the growing blood pool at her feet.
Dawn rushed passed her, rolling Angel over onto his back.
"Angel!" she called, shaking him.
His wide-dead eyes stood staring at nothing.
Buffy looked down into those eyes.
"I...he...but...he died...he...he was evil...oh god what have I done?" she cried, dropping the bloody stake like it was poison. She lifted her hands to her face, to hide from the shame and horror, but saw a splash of his blood on her fingers.
She hadn't stake Angelus, she had murdered Angel.
"He wasn't a vampire? But…what did you do!" Dawn cried again, sobbing over Angel's body.
Suddenly Buffy's phone began to ring. In a fog, Buffy answered.
Willow's voice sounded from the speaker, "Buffy! I did a locator spell for Angel's soul! It's in Rome, right near you! And you're not going to believe this, but he's human Buffy! Angel's alive and still human! Buffy? Did you hear me? Angel's alive! Isn't that amazing!"
Buffy stood staring at Angel's corpse.
"I have to go." she muttered, the dropped the phone.
It cracked against the cold asphalt.
She turned, body numb, and disappeared into the night.
Dawn's cries fading until there was only the sounds of the night.
...
Buffy stood at the bridge she'd stood with Angel over three weeks ago.
Her thumb trailing the banister where his had rested as they spoke.
A hand that had been warm.
A hand that was now cold.
A hand that would stay cold.
There would be no reanimation into a vampire for him...not since she staked him to death not ten minutes ago.
A sharp stake to the heart and it was over...forever.
A single tear fell down her cheek.
She looked down over the edge, watched the water as Angel had three weeks ago.
Without another thought, she leaned over.
Her body felt the cold water as it consumed her.
She was disappointed the fall didn't kill her, but not to be denied in death again, she took a deep breath.
And another and another, her lungs nearly bursting with the cold water.
She didn't mind the pain, the horrible convulsions as her body called for air, the feeling of drowning.
It didn't take long, her slayer powers rendered null as her heart stopped beating.
Somewhere in the world, another slayer was called.
...
The End.
…
I bet you like my version one ending now don't you?
I'll post a 'good' ending…look out for it.