Nagini.
While Professor Lupin was teaching his class of young wizards, far away in Austria, Geralt felt somewhat at a loss. It was his first time conducting this particular form of tracking. There was no need to engage his Witcher senses, painstakingly hunting for fallen footprints, lingering scents, or personal belongings; he didn't even need to carefully conceal his presence. He was simply trailing the target in broad daylight, right out in the open.
No matter what commotion he made, or how close they got, the person ahead acted as though he couldn't see him at all. If the distance grew too great, the man would even pause and intentionally wait for a while.
Chapter 368