And so after Sidious had returned to Coruscant, he had devoted himself to internalizing that ability, by manipulating the midi-chlorians that animated him. For several months he made no progress, but ultimately he began to perceive a measured change. The scars that had grown over his wounds had abruptly begun to soften and fade, and he had begun to breathe more freely than he had in twenty years. He began to sense that not only were his damaged tissues healing, but his entire body was rejuvinating itself. Beneath the transpirator, areas of his skin were smooth and youthful, and he knew that eventually he would cease to age altogether.

- Chapter 24