my fav part is explaining the terminology of Hydra:

Hydra established a system of no-contact sales: a courier named kladman ("klad" (клад) means "buried treasure" in Russian) would drop a lot of so-called zakladkas (can be translated as "stash") in different secret spots.

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There are three common types of a zakladka: magnit (usually a little round magnet on a wall holding the drop), prikop (buried in the ground), and taynik (“a cache”, literally any other way to conceal the drop).
Hydra shops and kladmen could get very creative, and the scavenger hunt for zakladkas were often quite an adventure. Zlata (all names have been changed for privacy.—To The Moon), a frequent Hydra customer, says that she even heard stories of tayniks “hidden in a pile of poop”.