Where It All Goes Down
London
London: the total center of civilization, where the bright lights of reason and progress are always shining, right? Well not according to Conrad. Throughout this book, London is a very dark and wet place. There seems to always be rain or fog. Also, there is almost always a sense of menace in the streets, as you get with the following description of horses and a carriage:
…the van and horses, merged into one mass, seemed something alive—a square-backed black monster blocking half the street, with sudden iron-shod tramplings. (7.102)
You have several not-so-cheery indoor settings such as the house of Michaelis' lady patron, the Silenus pub, the Professor's apartment, and the Verloc's shop and home. These locations are neither light-filled nor pleasant: they suck. For example, the Silenus Restaurant is supposed to be a nice, warm place, but Conrad only talks about:
Bronze chandeliers with many globes depended from the low, slightly vaulted ceiling, and the fresco paintings ran flat and dull all around the walls without windows. (4.1)
Sheesh, Conrad. Did you really need that bit about no windows? Even if the place had them, it'd be a super grey day outside anyway. As you've probably noticed, everything in The Secret Agent is always dreary and dark, and in general, tends to reflect just how unpleasant and soul-crushing turn-of-the-century London was.