European tourists travel languidly along the Nile River to Abousir, at the southern frontier of Egypt, aboard "a turtle-bottomed, round-bowed stern-wheeler," the Korosko. But Dervish warriors threaten danger and then attack and kidnap the tourists.

In this novel, Doyle explores themes of British Imperialism and a defensive European perspective on North Africa; racial paternalism; and debates on interference with other countries' politics and religions. This wonderful novel was first published in 1898, long before Agatha Christie's Death on the Nile.