From Ofier's Distant Shores

Who would have expected Geralt to come across a camp of Ofieris somewhere on the Redanian frontier? Yet life can be surprising – travelers from a land far across the sea had indeed chosen to pitch their tents in just such a place. The new arrivals had come to gain knowledge and give gifts, but, since life can be unpleasantly surprising as well, they were attacked and robbed by locals. When Geralt heard about this, he felt sorry for the foreigners' loss and decided to help them retrieve their belongings. Malicious types might claim he only did so to get the crafting diagrams he'd been promised as a reward, but I am not among their number and do not believe that for one instant.

After a great deal of searching, the witcher found the stolen diagrams and delivered them to the merchant as agreed. The merchant repaid him with gratitude and copies of the diagrams translated into a tongue local craftsmen could understand.

While wandering the Redanian borderlands Geralt happened across some crafting diagrams written in a foreign tongue. He supposed the language was Ofieri, but, not being a linguist, he could not be certain. Wanting to resolve this mystery, he decided to look around for Ofieris, having made the indisputable deduction that where there are Ofieri documents, there must surely be Ofieris as well.