Darkness consumed the mind of Darth Vader.

For a few moments, surprise had frozen him. Then, anger rose and became black rage – rage that swelled and grew and lashed at everything around him. Rage at the Jedi, who had stolen not one, but two children. Rage at Obi-wan, who had dared to hide his daughter in plain sight. Rage at Bail Organa, who had allowed Leia, his child, to join the Rebellion, which led to her involvement in stealing the Death Star plans, which led to her capture by her own father aboard the Tantive IV, which led to the Death Star, and a dark cell, and an interrogation droid…

And then the rage receded, to be replaced by horror and guilt and grief. Memories and images and remembered conversations assaulted him.

A prosthetic hand rubbing a pregnant belly.

"With that kick? It's a girl…"

"If it is, what shall we name her?"

"I like the name Leia."

"And now, your Highness, we will discuss the location of your hidden Rebel base."

"Her resistance to the mind probe is considerable. It will be some time before we can extract any information from her."

A blue-green planet, blown into a billion pieces into the darkness of space.

The anguish of a teenage princess, held back by his own brutal hands.

Dark brown eyes in a heart shaped face, filled with tears as her loved one was lowered into carbonite.

The howl of a Wookie.

"Father?"

Vader's focus shifted. Who was that?

"Father!"

Luke. Luke!

His vision cleared and he looked around in disbelief. Luke was standing in front of him. The room was completely destroyed. The main lighting was out, though emergency lights had clicked on.

He was suddenly aware that the main window had been shattered in his frenzy, and was now open to the Coruscanti atmosphere. He and Luke were potentially at risk from observers or worse yet, snipers.

He grabbed Luke's arm and pulled him into his chamber next door, barely remembering to turn off his son's shock collar in time to prevent a painful jolt.

Luke's quarters had been specially reinforced in case of attack, and thus Vader's own quarters hadn't sustained significant damage. He moved numbly to a com unit, and quickly sent an order to secure the now breached section of the palace. He didn't bother to see what Luke was doing. If his son chose to attack him during this moment of vulnerability, so be it. He deserved it.

But Luke didn't. After Vader had finished the com, he turned slowly towards his son.

The look on Luke's face was one of trepidation.

"I tortured my own daughter," Vader said dully.

Luke's expression shifted to one of surprise, mixed with hope.

"And you regret it?" Luke asked.

"Of course I regret…"

He paused, considering Luke's words. A Sith Lord shouldn't grieve over inflicting pain, even on his own daughter, should he?

And he did grieve. He would do anything in the world to go back in time and change was he had done. But of course that was impossible. He had inflicted tremendous pain on both his children, and there was nothing he could do about it.

He suddenly focused on his son.

"Are you injured?" he inquired anxiously.

"I assure you, Father, that after Bespin I made rather a point of learning to deflect large objects thrown at me. I'm fine."

Vader winced at this reference to Bespin, but nodded in relief.

There was a moment of silence between the two men.

"How long… have you known?" Vader inquired carefully.

Luke considered briefly, then answered, "About a year."

"So you didn't know…"

"At Bespin. No."

Vader stared unseeingly at the floor.

"When your mother told me she was pregnant, she was certain the child was a boy. And I was certain the child was a girl. And we were both right."

He looked up at his silent son.

"Does your sister know?"

"Of course she does," Luke said flatly, "I had no intention of making the mistake with Leia that Obi-wan made with me. As soon as I could, I told her."

Vader hesitated, then said painfully, "And…her reaction?"

"Horror, anger, resentment, and grief. All the reasonable emotions."

Vader turned away, "I am sorry, Luke."

"You can't change the past, Father. You can affect the future."

Vader sighed, "It is too late for me, Son."

Luke stepped forward and somehow managed to peer past the mask and straight into his father's eyes, "You are right, Father. It is too late to undo the last 24 years of horrors you have inflicted on the galaxy. You can't change what happened to Leia on the Death Star, and to both of us at Bespin. But you can change what you do now. You have the power to alter the galaxy for the better – probably more power to do that than anyone else alive. It is your choice."

Vader shook his head, "I've been immersed in the Dark Side for too long, Luke."

"That is just an excuse, and you know it. You have already changed so much since Bespin, Father. I can sense it, you must feel it too! "

Luke reached out a hand and lay it gently on his father's arm, "You were a slave to Palpatine for more than 20 years. He's dead now, and you are free from his diabolical influence. Please, turn away from what has brought such sorrow not to just to our family, but to the galaxy as a whole."

Vader looked at his son in amazement. Could he really change? A part of him wanted to, while another part wondered if it was possible or even remotely desirable. In some ways, he still loved the Dark, loved the rush of power that came from falling headlong into the vital emotions of rage, ambition, and even fear. He craved the power, and the control, over his life and over the lives of the billions he now ruled. He had longed for this position of senior Sith Lord for so long. He had envisioned a glorious and powerful reign with his son at his side. How could he even fathom giving that up?

But his son stood before him, filled with hope that he would and could change. His son who had categorically refused to join him in the Dark Side. His son who had already suffered tremendously at his father's hands and yet wasn't treating Vader with hatred and disdain, but instead compassion, perhaps even love.

He had to face reality: the quick and easy path of the Dark Side had brought tragedy to the most important people in his world, his wife, his son, and his newly discovered daughter.

He wasn't sure he could change. He wasn't sure he wanted to. But he at least would consider it.

And with that, the soul of Darth Vader took one tentative step towards the Light.

Author note: All good things come to an end, including Christmas break. I will be way busier now that "normal life" is starting back up. I have 2 more chapters mostly completed, then I likely won't be able to maintain this "one new chapter a day" schedule :-). Many thanks to those of you who are reviewing and following.