In the sixth novel of his Galactic Center epic, Benford brings the series to a dramatic close with a peek into humanity's future 37,000 years hence. Nigel Walmsley, twentieth-century Earth's first starship traveler, who figured in the saga's first installment, In the Ocean of Night (1977), returns to recount recent adventures inside the Esty, an anomalous shelter of space-time existing outside a black hole near the galaxy's true center. Walmsley's listener is Toby Bishop, the adolescent protagonist of Furious Gulf , whose family and fellow humans have been decimated by an insidious, machine-based life-form known as the mechs. Together, Walmsley, Toby, and the remnants of Toby's family must find the means to outwit the mechs before they penetrate the Esty and destroy all trace of humanity.