Guardian of the HorizonMass Market Paperbound, 30 August 2011

From the lost journals of archaeologist Amelia Peabody comes a chronicle from the "missing years"--a tale of adventure, bravery, and terror.

Readers have long wondered what befell the Emerson clan during the years before the Great War. Now, at last, the silence is broken and the truth revealed of a perilous journey to a secret and mysterious place hidden deep in the heart of the unforgiving desert. An adventure prompted by loyalty to an endangered friend--and spurred on by lies and treachery--leads Amelia Peabody and her intrepid family into a nest of vipers lying in wait at a remote mountain fortress. And when a dark past and a shocking mystery are ultimately discovered, a loved one may be lost forever.