Thrust, parry, riposte, slash, block, parry, parry, slash, clash… the rhythm of battle went back and forth, the two men spinning, twirling, ducking, parrying, and all the while the Clone Troopers stood paralysed, waiting for instructions from a man who no longer had any interest in giving them.

For what did Castor Voraainsar have to lose? His eyes blazed yellow with the venom of hatred that is the mark of all Sith. His sabre was red with the blood of innocence lost. Every move he made, he made in anger.

If once you start down the dark path, forever will it dominate your destiny.

Yoda had been right.

There was no way back now.

--

Luna Lovegood led Mace up the stairs of Hogwarts, using the Force to cloud the minds of the Clone Troopers that filled the halls. Mace's confusion was a beacon in the Force – she began to wonder just how badly the Jedi had hit his head when he landed in her car.

"I don't understand," he said to her, glancing around the unfamiliar hall. "What are we doing here? What are the Clones doing here?"

Luna didn't answer, but cocked her head, listening to the voices.

Your former Master is in grave peril, the man's voice said. He lies on a precipice. He mistakes his grief and sadness for true submergence in the dark side.

I should never have begun anything with him, the female voice said. If I had known…

Known what? The man's voice asked. Known that you would make him happy? Known he would die and kill for you? You've done more good than harm for him.

But still…

"Sorry, you aren't helping," Luna said to the two of them. "None of this tells me how to stop him and save him."

"Stop and save who?!" Mace said from behind her, exasperated.

"Sh, don't interrupt!" Luna said, then she cocked her head again, and then, after a moment, she smiled.

"Oh well, that's going to be easy!" she said. "Come on then!"

--

Castor Voraainsar blocked another blow from Harry, and then smiled, making a faux salute.

"You're doing well," he said, half serious, half mocking. "Try harder and you might…"

The next blow struck his robotic arm, smashing it to pieces. Castor staggered back.

"You…" he laughed. "Hah! You win, Harry. You win…"

Harry spun his blade and aimed it right at Castors chest.

"Give me a reason not to kill you," he said, slowly emphasising every word. "One reason."

"There isn't one," Castor sneered. "Do it, Harry. Do it."

Harry blinked, and hesitated. He pulled the arm back.

Don't.

He paused, as the voice he had not heard since he was a small child came to him.

Don't, Harry.

"Qui Gon?" he murmured. "You're…?"

Castor took the opportunity to summon his sabre to his good hand and begin attacking again, but in his weakened state, he was easy pickings, and Harry sliced the blade in two, before aiming the sword back at his former friend's heart.

"Don't!" came a more concrete voice, and then, Luna Lovegood and Mace Windu raced into the room. Clones aimed rifles at them, but Luna held up a hand, and they dropped them again.

"Hello, Castor," she said, her voice tinged with a certain sadness. "You are alive."

"Luna Lovegood," Castor Voraainsar sneered. "My old Padawan. I should have realised you'd have survived."

"Perhaps," she said, inclining her head, unsmiling. "But then, if you had, you wouldn't be here. You'd have run away, like the Sith always run from justice."

Castor stopped smiling. Luna blinked once, frowned, and then ignited her azure lightsabre and threw it right into him.

--

Castor blinked.

He was dressed in Jedi robes, unsullied and simple. Opposite him was a man with his hair, his face and his smile, wielding a red lightsabre and pointing it right at him.

"What is this?" he asked.

"This," a familiar voice, one etched into his soul forever, spoke, from his side, "is the mental plane."

Castor didn't dare believe his own ears. He turned his head, slowly, and there, resplendent in Jedi robes, yellow blade ignited, was Kara Vincennes, smiling her old smile.

"I'm dead," Castor said.

"Oh no," Kara said, the same smile upon her face. "You aren't dead. Not yet, anyway."

"But you are," Castro pointed out.

"Oh, yes," Kara admitted cheerfully, "but you aren't me – and I'm not you, which, considering him," she nodded at the duplicate Castor with the red blade, "is probably a good thing."

"Kara, I," Castor began, filled with the urge to repent to her, admit his faults to her right there and then, but then she held up a hand.

"Nothing to forgive," she said. "The stain that is Darth Mortis is not you – it's an echo of you, of what you are and what you feel."

Castor looked over at his doppelganger. "Is that what he is then?"

"Yup," she said. "And that's what we have to face."

"You mean?" he said, and then she handed him a replica of his old blue lightsabre, which felt warm to the touch. He ignited it, and looked right over at the Mortis figure.

"Together," she said. "We defeat him, and you go home."

"I go home?" he repeated, looking at her in dismay. "But I want to stay here, with you!"

"You'll come back," she smiled. "One day. I promise. Now…"

She raised the blade in her hand, and charged. Castor looked right at her, and followed.

--

"We heal the damage to his body, and Kara heals the damage to his soul," Luna finished, having explained everything she could to the assembled Jedi Knights. She was using her wand to restore Castor's lost arm.

"He's a Sith," Mace Windu said. "After all he's done, he has to die."

"That," Luna said sharply to him, "is precisely why Anakin turned. Because you were such an uncompromising Jedi."

"But will Kara be able to restore Castor?" Harry said. "Master Yoda always said…"

"We'll know…" Luna said, and then she paused, listening for advice. "We'll know in a moment. Kara's returned to the Force."

Castor stirred, his fists clenching, and then, his eyes snapped open.