The Fall of The Congo Arabs by Sidney Langford Hinde Chapter 11 Page 19

swamp above mentioned. Selimani's business was to inquire into the affair, and to tax Ali with it, who it was thought, knowing that his trick was discovered, would be afraid to carry it out. Selimani had hardly started when de Wouters repented of having sent him alone. Fearing lest Ali might take it into his head that Selimani was the only man who knew of the plot, and might murder him on the spot, he quickly sent a corporal with five-and-twenty Hausas into the grass after him.

The Hausas, passing the word round in their own language (which even their wives could not understand), slipped into the grass on different sides of the town, and, completely hidden by it, joined the corporal one by one in the swamp, from which they were able, unobserved, to approach All's camp to within twenty-five yards.