Not too surprisingly, having something that's in his eye socket burned is... not exactly comfortable. And, even if the rose isn't actually a part of him, its magic is.

The pain starts out dull and burning, just inside his eye socket - and then it spreads, sharpens, like needles in his skull. He struggles all the harder, his muffled protests becoming louder and more insistent, until, if it weren't for Foster's hand over his mouth, he'd be screaming outright.