Summary: Obi-Wan makes a different choice on Mustafar.
Disclaimer: I do not own Star Wars. On a more specific note: the first five lines of this fic (and of course the quote at the beginning) are lifted directly out of the Revenge of the Sith novelization, and belong to Matthew Stover.
Notes: This is the starting point to an alternate continuity that basically asks the question, "What if the only people Vader cared about didn't die/leave him to burn slowly to death, and he actually had to deal with the long-term emotional consequences of his actions?"
at the crossroads of immolation
"Nothing will happen. Nothing can happen. Let Palpatine call himself Emperor. Let him. He can do the dirty work, all the messy, brutal oppression it'll take to unite the galaxy forever – unite it against him. He'll make himself into the most hated man in history. And when the time is right, we'll throw him down." – Anakin Skywalker, Revenge of the Sith by Matthew Stover
Obi-Wan knelt beside Padme's unconscious body, where she lay limp and broken in the smoky dusk. He felt for a pulse. It was thin, and erratic.
"Anakin – Anakin, what have you done?"
In the Force, Anakin burned like a fusion torch. "You turned her against me."
Obi-Wan looked at the best friend he had ever had. "You did that yourself," he said sadly.
"I'll give you a chance, Obi-Wan. For old times' sake. Walk away."
A response caught in the back of Obi-Wan's throat as he stood, looking down at the woman who he had come to think of as a dear friend. Unbidden, a memory came to the forefront of his mind: the Well of the Dark Side, so very much like Mustafar, where Anakin had fallen the first time. Where Obi-Wan had convinced himself that he had been infected by the Son, as Ahsoka had. Only now there was no Father to erase Anakin's decision, and no way to undo the damage he had done. Too many had already died at his hand.
He thought of his dead comrades, slaughtered by Anakin; of all the people he cared for that had died in the Clone Wars, and before. He thought of Qui Gon and Siri and Satine. Because he knew then, with the certainty imbued by the Living Force, that Padme would die if he did what Yoda had sent him here to do. He knew also that Yoda would not defeat Sidious. If he fought Anakin here, and won, then Palpatine would simply acquire a new apprentice. And if he lost and died, his knowledge, and likely the future of the entire Jedi Order, died with him.
Padme would die in either case, her life draining away as he and Anakin fought a meaningless battle. And Obi-Wan just couldn't let that happen. There was no greater good to be had in the sacrifice of Padme Amidala. In fact, he was certain that her death would plunge the galaxy even further into darkness.
And so Obi-Wan found himself saying, "Is that a sincere offer, Lord Vader?"
He felt more than saw Anakin's surprise. "It is," said Anakin.
Obi-Wan nodded once. "Then I shall take my leave. But...if I may offer one last piece of counsel?"
"Of course you must have one last lecture, Obi-Wan. I wouldn't deny you the pleasure."
Obi-Wan sighed, and felt something warm trailing down his cheeks – barely perceptible against the oppressive heat of Mustafar. "I overheard your plans for dealing with your new Master. As abhorrent as I find them, they are...logical. But they will require that you allow him to live for some time to come." He looked at Anakin, his voice calm in spite of the tears that continued to slide down his face. "You know this of the Sith, Lord Vader: there can be only two. Your child will be strong in the Force, as you are, and Sidious will no doubt see that child as a threat to be eliminated, or an asset to be controlled. He will certainly use both Padme and the child as a way to control you, since you do have such trouble following orders. Please be mindful of these dangers."
Anakin sneered. "You underestimate me. With the power of the Dark Side, I'm more than capable of protecting them both."
And who will protect them from you? Obi-Wan put the thought aside, swallowing his instinct to argue. Anakin would see for himself soon enough that it was he who underestimated Sidious.
"As you say," said Obi-Wan, with an almost deferential bow of his head. "In any case, please get Padme to a med center. I fear that the life of your child is in danger." He turned around, walking to Padme's private yacht. Before he boarded it, he said, "I snuck aboard the ship without Padme's knowledge. She had no intention whatsoever of bringing me here, and tried to hide the fact that she knew of your location. If you search your feelings, you will know that I speak the truth." He walked up the loading ramp, but paused again before closing it. Forcing himself to turn around, he looked at Anakin Skywalker: his greatest failure, and the man he loved more than any other being in the galaxy. "Goodbye, Lord Vader."
"No 'may the force be with you'?" said Anakin, with cruel sarcasm. "I'm hurt, Obi-Wan. Truly." Even now, Obi-Wan could read his former Padawan like a datapad, and knew he was unsure of this decision. Was probably deciding if he should kill Obi-Wan after all and force him into a confrontation.
Oh, Anakin. Am I not living up to your grand fantasies of retribution? I know full well that you've surpassed me. "We both know that the Force is with you already," said Obi-Wan. "I hope your Empire proves to be the force for good you envision, Lord Vader. May we never meet again."
With that, he closed the ramp, and left his best friend – his brother – behind forever.