The Book of Skulls (Robert Silverberg, 1972)

Candidates for eternal life must present themselves at the "Skullhouse" as a foursome. The brothers are happy to provide training in their secrets (including tantric sex) - but there's a price. The Ninth Mystery in the Book of Skulls states: "Two of thee we undertake to admit to our fold. Two must go into darkness". One of those four college students must willingly commit suicide. One is fated to be murdered by his own friends.

The narrative shuttles between their viewpoints, each distinct and sharply characterised. Rich, handsome, upper-class Timothy doesn't believe in immortality and is just going along with the gag. Eli the Jewish intellectual believes passionately. Ned, who is openly gay, has his own agenda involving Oliver, a Midwestern farm boy with tortured depths who says the Skullhouse is his only hope. Each in turn undergoes an ordeal of dreadful self-knowledge, after which the impossible choice of who wins and who loses seems natural, even inevitable.