The Seekers of Truth aren't templars... not precisely. Once they were called the Inquisition, but upon the signing of the Nevarran Accord, they gave up that name and became the Order they are now, standing over us templars as watchers and enforcers. I honestly cannot claim to know more than that. I don't know how many Seekers there are—a few dozen? If they have a base of operations, I don't know where it is. Certainly not with any of us. The only time we'll see one is when a Seeker is summoned, perhaps in response to a complaint by one of the first enchanters. They'll investigate the problem, and if it turns out a templar did something they don't like, he's disciplined. Severely. Without question. Even the knight-commander bows to their will. If a Seeker of Truth shows up, you know every last templar is sweating, hoping their gaze doesn't fall on him.
Of course, that changed when the Nevarran Accord was broken. I'm told the Chantry broke it, but it was Lord Seeker Lambert who made the announcement. He said the Seekers of Truth and the Templar Order were going to hunt rebel mages, no matter what the Divine commanded. I didn't know he had that authority, that he could just say we would do this and everyone would follow... but we did. I never thought of it that way, but the Seekers have always been our guides. Now they've led us into war.
—From a letter written by Ser Jonathan Perry, 9:40 Dragon