After Ilana's death, Hurley finds a Russian-language copy of Fyodor Dostoyevsky's 1864 novel Notes from Underground in her things. (Was Ilana studying up on her enemy?) Hurley also finds a pouch that may contain either some of Jacob's ashes, or the black and white stones—which seem to represent light and dark, or good and evil.
Presenting several Lost themes such as the relationship between the individual and society, definitions of truth or reality, determinism versus free will and the meaning of morality, Notes from Underground is a rejection of socialist utopianism. It highlights the idea that anyone at any time can act in a way which may or may not be considered "good"—since good is a subjective, relative term. (For example, was Hurley's decision to blow up the leftover Black Rock dynamite good?) A primer of existential thought, the book is said to have inspired philosophers like Jean Paul Sartre, Friedrich Nietzche, as well as writers such as Leo Tolstoy, Ralph Ellison, Joseph Heller, Richard Wright and Bret Easton Ellis.