The Golden One - Elizabeth Peters

At the start of this fourteenth adventure for Amelia, which continues the wartime theme begun in Lord of the Silent, it is New Year's Eve, 1917.Risking winter storms and German torpedoes, the Emersons are heading for Egypt once again: Amelia, Emerson, their son Ramses and his wife Nefret. Emerson is counting on a long season of excavation without distractions but this proves to be a forlorn hope. Yet again they unearth a dead body in a looted tomb - not a mummified one though, this one is only too fresh, and it leads the clan on a search for the man who has threatened them with death if they pursue the excavations. If that wasn't distraction enough, Nefret reveals a secret she has kept hidden: there is reason to believe that Sethos, master criminal and spy may be helping the enemy. It's up to the Emersons to find out, and either prove his innocence or prevent him from betraying Britain's plans to take Jerusalem and win the war in the Middle East.