Death in a Desert Land

Baghdad, 1928. Agatha leaves England for the far-flung destination, determined to investigate an unresolved mystery: two year ago, the explorer and the writer Gertrude Bell died there from a drugs overdose. At the time, the authorities believed that Bell had taken her own life, but a letter now unearthed reveals she was afraid someone wants to kill her...
In her letter, Bell suggests that if she were to die the best place to look for