A group of European and American tourists is enjoying its trip in Egypt in the year 1895. They are sailing up the River Nile in a "a turtle-bottomed, round-bowed stern-wheeler", the Korosko. They intend to travel to Abousir at the southern frontier of Egypt, after which the Dervish country starts. They are attacked and abducted by a marauding band of Dervish warriors. (Wikipedia)