There was no reason for him to keep fighting! His friends had escaped, he was clearly outmatched, and yet he persisted. There was a faint whisper at the back of Vader’s mind that Luke fought so desperately because he thought that he had to. But the greedy hiss of the darkness drowned it out.

Luke’s energy was flagging, but he rallied, and batted away Vader’s lightsaber with an impressive strength in his swing. For someone with absolutely no formal training, Luke had a power to his stance, and even to his clumsy parries and thrusts, that was gratifyingly intimidating. He was going to be a force to be reckoned with one day. 

Provided he just stopped resisting.

The blades sparked and hissed against each other in a brilliant flash of light, then Luke ducked another lunge. This was beginning to grow tiresome. Their time was growing ever shorter, and the emperor would not accept another excuse. When the boy lashed out and caught Vader with a glancing blow to the shoulder, his fury overtook him. Again and again he slashed at that blasted blue blade, that insidious reminder of a man who was dead- a life that no longer existed- until he could feel Luke’s muscles trembling under the strain.

With a particularly vicious momentum, he swung-

And the boy screamed.

His hand-

His hand was-

The lightsaber -- his lightsaber -- tumbled down into the empty shaft below. Luke fell to his knees, clutching the stump of his right wrist. His face was twisted in pain.

Darth Vader had not had a right hand of flesh and blood for longer than Luke Skywalker had been alive. And yet, for a brief instant, he swore that it was his wrist that burned, that it was his scorched flesh that he could smell, in spite of the mask’s filters. 

Look! The Force suddenly clawed at his mind, denying him the chance to retreat into the comfort of his rage. Look at what you have wrought. 

Luke was so…

Small. 

He was so small, there on the ground. Huddled. Was he trying to present a smaller target? Or bracing for a killing blow? 

“He is just a boy.” 

His own words rang mockingly in his ears.

“Just a boy…” Darth Vader said aloud.

As if the revelation had only just hit him, he stumbled back a step. “You’re just a boy.” 

Luke looked up slowly, inching backward. The fear rolled off him in waves, shimmering like heat. He was confused, and disoriented, and very close to shock.

“I’m-”

What was he to say? What was there to be said?

“Ani...something wonderful has happened.”

Had he been so prepared to maim when he’d first learned the boy’s name? Or was his desperation fueled by the emperor’s recent discovery of Luke’s survival?

“This is the happiest day of my life.” 

Would that naive boy have said the same thing if he had known that only twenty-two years later he would be staring down at the bloodied, beaten form of his own terrified child? That he would be the one responsible for the pain in his eyes?

How had it been twenty-two years?

How had it only been twenty-two years?

“My boy…”

The words fled his heart before he could stop them.

Luke’s eyes widened, and he pulled farther away. Too close to the edge.

“M’not your boy,” he rasped harshly.

But Vader barely heard him. Slowly, so slowly he knelt, lightsaber falling from his slack hand. The hilt bounced once, and deactivated with a snapping hiss. One inch higher, and he very well could have killed the boy. His boy.

“I…”

Vader had never been a conversationalist. He certainly wasn’t going to start now. But Luke seemed to have finally noticed that something was wrong.

“I’m…”

Hot shame began to burn in his gut, just a twinge at first, building into a bonfire. 

“Something wonderful has-” 

“I could have killed you,” he breathed. “I almost killed you.”

Confusion tinted Luke’s eyes, swimming with pain. “What are you talking about?” he asked with as much suspicion as he could muster.

It wasn’t supposed to go this far. He was supposed to have trapped Luke in carbonite -- spirited him away to the old fortress on Vjun his master had forgotten about when the castle on Mustafar was built. He was supposed to have released Luke there, and broken it to him more gradually that he had been lied to.

It wasn’t supposed to go this far.

Sith Lords did not regret.

But Darth Vader did.

“The only good thing I ever put into this universe,” Vader marveled, a thread of emotion coloring his fearsome baritone, “And I almost killed him.”

Carefully, almost reverently, he reached out. His hand dwarfed the boy’s face as he lifted his chin. “My boy…”

Luke’s head jerked back. “You...you’re crazy!” he gasped. “You didn’t- you killed him! Obi-wan told me. My father was Anakin Skywalker!”

The gentle grip on his face shifted, and then without warning he was pulled forward. He cried out in both fear and indignation as Vader wrapped his arms around him.

“Yes,” the Sith murmured, “I was.”

The words registered slowly. Piece by piece, syllable by syllable, they marched mercilessly into Luke’s heart. He wanted to scream, to close his ears to it. But the Force detected no lie.

A hand covered the back of Luke’s skull, pressing him against Vader’s tabard and breastplate. Vader was…

Vader was trembling.

Luke could feel it now. Vader was trembling. 

“Luke,” his enemy murmured, almost too low to be heard over the wind. “Oh, my son. I almost killed you. So many times, I almost killed you and I never even knew-”

He drew back enough to allow him to look more closely at the boy. Horror was etched across his features. The truth was beginning to sink in.

“Obi-wan told me you killed my father,” Luke whispered in a meaningless denial.

“Obi-wan lied,” Vader answered.

Luke shook his head wildly. “No!”

Vader caught hold of his face between his fingers again. “Obi-wan. Lied.”

He brushed away a tear that was beginning to slide down the boy’s cheek.

“Oh Luke…”