Book excerpt: Swimming in a Sea of Death is David Rieff's loving tribute to his mother, the writer Susan Sontag, and her final battle with cancer. Rieff's brave, passionate and unsparing witness of the last nine months of her life is both an intensely personal portrait of the relationship between a mother and a son, and a reflection on what it means to confront death in our culture. David Rieff confronts his feelings in relation to his motherandmdash;the guilt, the self-questioning, the sense of not having done enough. And he tries to understand what it means to desire so desperately, as his mother did to the end of her life, and to try almost anything in order to go on living.