The difficulty is the go-between." Ethne looked quickly at Durrance.
"The go-between ?" she asked, and then she said, "I think I begin to understand," and pulled herself up abruptly.

"You mean the Arab who can come and go between Omdurman and the Egyptian frontier ?" "Yes.

He is usually some Dervish pedlar or merchant trading with the tribes of the Soudan, who slips into Wadi Halfa or Assouan or Suakin and undertakes the work.

Of course his risk is great.

He would have short shrift in Omdurman if his business were detected.