What happens in death?
Same thing that happens to every one else at death. No one can say for sure. But Buddhism does not really focus on what happens after death, it focuses on what happens here and now. Answer: As death and re-birth are central to Buddhist practices there is a considerable amount of material on the process of dieing and the stages leading to re-birth. The Tibetan "Book of the Dead" is instructive in these matters
Secularism is simply the belief that religion and the state should be separated. A religious secularist will believe that whatever that person's religion argues will happen after death. A non-religious secularist will usually argue that nothing has been proven about what happens after death and all signs point to nothing occurring, so they do not believe anything about what happens after death.
Death is what happens to Polybus in "Oedipus Rex" by Sophocles (495 B.C.E. - 405 B.C.E.). Specifically, Corinthian King Polybus dies of illness and old age. His death happens while he is in Corinth. He is supposed to be succeeded by his presumed son, Theban King Oedipus, who is ruling in Thebes when the death occurs.