It’s the spring of 1877 in Washington, D.C., and at the U.S. Naval Observatory, great changes are afoot: historical, romantic, and scientific. When the brilliant Cynthia May—a Civil War widow whose beauty has been shadowed by worry and poverty—starts work as a human “computer” at the Observatory, astronomer Hugh Allison has found just the partner he needs for a radiant, half-crazed scheme that will make him live forever in the annals of science and space. But first the two scientists must overcome the very earthly obstacles presented by powerful Senator Roscoe Conkling of New York and a fraudulent astrologer who just might know their future. Masterfully combining historical detail and startling invention and bringing Reconstruction-era Washington to life along with the ambitions of the burgeoning American nation, acclaimed writer Thomas Mallon gives us a galvanizing story of earthly heartbreak and other-worldly triumph.