To Zinkoff there is not one darkness, but many. There is the dark in the closet and the dark under the bed and the dark he can never see: the dark inside a drawer.


My instinct tells to use darkness rather than all of the "darks" in the above. Correct me if I am wrong. Thanks.
I wouldn't; it reads fine as it is.
I think your instinct is correct in the sense that "darkness" would be the more likely choice in "non-creative" writing. However, the sentence reads fine to me in context. "dark" seems more poetic (as well as having the advantage of being a shorter word).
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