The Collectors are a loose affiliation of individuals who acquire (and use) various items of power known as Relics.
These individuals collect and trade (sell) these items for their own personal reasons. They usually keep a low profile, and have no governing body or code of conduct except the One Rule: Don't get caught.
There are a number of individuals involved with the Collection Agency who are not Collectors. These individuals, known as "the Tradesmen", are various specialists who provide services to the Collectors (and each other). They are identified by their title, rather than their names.
These Tradesmen will, as they get old and think about leaving the Agency, take on an apprentice. This apprentice is know by that title (e.g., "The Locksmith's Apprentice").
Some of these people do it for money, others for fun, others for various personal reasons.
"The Locksmith" (Gertrude Bohlman) -- Expert at solving puzzles and ancient codes.
"The Auctioneer" (Lester Dettman) -- Facilitates and negotiates the trade and sale of items.
"The Coyote" -- Smuggler
"The Librarian" -- (Allison Baker) Researcher and archivist of folklore, facts, and trivia
"The Professor" -- Historian and appraiser, verifies the authenticity of the items.
"The Binman" -- Destroys dangerous or damaged items
"The Casket-Maker" -- Builds storage and display cases for the items, usually including materials to offset any negative effects.
"The Shopkeeper" -- Trades in Tokens and Curios, and ancillary items related to them.
There are a number of brokers who work strictly as intermediaries between collectors. Some work alone, others work in pairs or small teams.
"The Numbers" are 2 partners who work together in Asia. They use code names (Mr. Five, Ms. Six) and ask that the buyers do so as well. They do basic research on their buyers to make sure that they aren't meglomaniacs, but don't otherwise bother themselves too much about what the items will be used for.