Codringher and Fenn was a famous law firm and detective agency in Dorian. It was founded, not surprisingly, by two men: Codringher and Fenn and had a reputation for getting the job done — for the right price.
For some time, Geralt (and probably many others) assumed that Codringher and Fenn were one and the same person; that Fenn was simply another of Codringher's convenient aliases. But while Codringher did use other aliases, Fenn did in fact exist, though he rarely chose to be seen.
In The Witcher computer game
In the game, we hear about the agency of Codringher and Fenn when detective Maarloeve claims to have trained with them. The glossary entry (below) in the game is taken from the novels. It alone suggests that Raymond's "investigative techniques" would likely be far from orthodox, if he did train with the firm.
Codringher and Fenn
"A famous pair of lawyers who ran a firm in Dorian until both partners died tragically under mysterious circumstances. At its height, the firm was retained by people from all over Temeria. If someone had difficulties, troubles, problems - they went to Codringher and Fenn. So the firm's clients quickly received proof of dishonesty and malpractice by their business partner. They could count on receiving credit from a bank without insurance or security. As one of a long list of creditors, they would be the only one to exact what was due from the company declaring bankruptcy. Their son would be released from the dungeon and cleared of all charges based either on irrefutable evidence or a lack thereof, because if evidence existed it disappeared mysteriously while witnesses retracted any earlier testimony. The wife's lover or the daughter's suitor would suffer complicated fractures in three limbs, including at least one upper one - all as a result of an unfortunate accident. And an enemy with a grudge or some other troublesome individual would soon stop being a nuisance, often vanishing into thin air. That's how Codringher and Fenn worked."
- Speaking with Detective Raymond Maarloeve