What's Bred in the Bone by Grant Allen

For a day or two more, Granville remained seriously ill in the dirty hut. At the end of that time, weak and wasted as he was, he insisted upon getting up and setting out alone on his long march seaward.

It was a wild resolve. He was utterly unfit for it. The hospitable Namaqua, whose wives had nursed him well through that almost hopeless illness, did his best to persuade the rash Englishman from so mad a course, by gestures and entreaties, in his own mute language. But Granville was obstinate. He would NOT sit down quietly and be robbed like this of the fruit of his labours. He would not be despoiled. He would not be trampled upon. He would make for the coast, if he staggered in like a skeleton, and would confront the robber with his own vile crime, be it at Angra Pequena, or Cape Town, or London, or Tilgate.