Your friend is right in one thing.

Uganda is a vital spot for the English, and a blow there will make their whole fabric shiver.

But how can we strike?
They have still the coast, and our supplies grow daily smaller.' 'We can send no reinforcements, but have we used all the local resources?
That is what I cannot satisfy myself about.

Zimmerman says we have, but Tressler thinks differently, and now we have this fellow coming out of the void with a story which confirms my doubt.

He seems to know his job.