Zen and the Art of Killing Your Self by Chris Crabtree

Zen is a misanthropic grad student of physics and religion who wants to kill his Self before it kills him, if he can figure out where he ends and it begins. Ellie wants to save him but he won't let her into his life. Her ability to surgically remove a soul's facade with her penetrating, laser-scalpel eyes terrifies him. She's every broken piece of him that's missing, but someone would have to die to get them together. Fortunately, an old friend sends himself on a recon mission to the afterlife, and Zen has to go home to bury what's left. Ellie insists on coming along to share the driving. There's just no arguing with her. Will it be a perfect opportunity for her to help him bury his Self along the way or can she save him before it's too late?