a flash of lightning in a serene sky

By and by I learned that, most appropriately, the International Society for the Suppression of Savage Customs had intrusted him with the making of a report, for its future guidance. And he had written it, too. I've seen it. I've read it. It was eloquent, vibrating with eloquence, but too high-strung, I think. Seventeen pages of close writing he had found time for! But this must have been before his--let us say--nerves, went wrong, and caused him to preside at certain midnight dances ending with unspeakable rites, which--as far as I reluctantly gathered from what I heard at various times--were offered up to him--do you understand?--to Mr. Kurtz himself. But it was a beautiful piece of writing. The opening paragraph, however, in the light of later information, strikes me now as ominous. He began with the argument that we whites, from the point of development we had arrived at, 'must necessarily appear to them [savages] in the nature of supernatural beings--we approach them with the might of a deity,' and so on, and so on. 'By the simple exercise of our will we can exert a power for good practically unbounded,' etc., etc. From that point he soared and took me with him. The peroration was magnificent, though difficult to remember, you know. It gave me the notion of an exotic Immensity ruled by an august Benevolence. It made me tingle with enthusiasm. This was the unbounded power of eloquence--of words--of burning noble words. There were no practical hints to interrupt the magic current of phrases, unless a kind of note at the foot of the last page, scrawled evidently much later, in an unsteady hand, may be regarded as the exposition of a method. It was very simple, and at the end of that moving appeal to every altruistic sentiment it blazed at you, luminous and terrifying, like a flash of lightning in a serene sky: 'Exterminate all the brutes!'

--Joseph Conrad, Heart of Darkness, 1899