A construction project beneath the National Mall unearths a terrifying secret dating back to the Civil War. It is a cache of bones preserved in amber and buried more than a century ago by a cabal of scientists to protect humankind. The scientists, led by Alexander Graham Bell, who helped found the Smithsonian Institution, were safeguarding a wonder like no other: the very secret of life after death. But this prize is linked to a horror from the ancient past, a horror that has remained dormant yet all too frighteningly alive in the marrow of those bones.