While there are many tradespeople's guilds in existence, most of them are managed by noble families of wealth. But when the subject of the Guild comes up, no family wants to take credit - or blame - for their activities. The Guild operates as a sort of underhanded go-between, the shadowy counterpart to the Glories that does all of the skulking business and leaves families and trade houses blameless for unfortunate events that may occur as a result of the Guild's dealings. They aren't exactly evil any more than the Glories are exactly good - and some adventurers are in both the Guild and the Glories, usually rogues.