Balkan is/was a rare book collector, he was working to find the Tril, and found the location, but wanted way too much money, so Percival refused to pay for the information.
Apparently he found another buyer, and they went to Russia to find it.
Percival and Lucien summoned Balkan, he arrived in the circle, covered in rags, emaciated, and broken. Currently Balkan, doesn’t know if he’s coming or going, if they found the book, only that he is lost…