Death and (im)mortality

With Halloween season in sight, the topic of death and (im)mortality seems appropriate. Moreover, there's a long history of SF presenting interesting twists on the subject! You are thus cordially invited to present one or more genre books (science fiction, fantasy, horror, etc) that deal with this topic.

Afterwards we will have a casual and friendly chat about the books, about the subject of death and (im)mortality, and wherever else the conversation takes us!

You are of course welcome to bring the books you want to discuss, but it's also fine if you don't.