Red Headed Lover on the Run (No One Knows)

Anakin looks no different from the last time they met. He is swaddled in a dark cloak and moves toward Obi-Wan with his lightsaber ignited. The new model is not unlike his old one, but its flame is bold and red.

Or, an AU in which nobody wins the Battle on Mustafar, and Obi-Wan finds himself lost.