Oh this one was going to be a challenge. An interesting, wonderful puzzle the he had to solve. He could already tell, and as tempting as it was to pump her with a full new dosage, he didn't want to temper with her mind permanently. Not yet, anyway. She was like the gift that kept on giving - one girl, multiple experiments. He could practically salivate with eagerness at the thought.
"Oh, there's always something." His voice was soft, as if he was telling him a secret that nobody else knew. "There's always something lurking right there, riiiiight under your skin. I'll help you figure it out. You'll see."
Despite not wanting to pump her full of toxins, he still injected the extra toxins into her system. Just to top her off for now before he let her rest. He had to pace himself. He had no problem killing people, or driving them permanently insane, but not until he was done. They were his toys until then, and Crane already knew that he had in front of him one of his favorites.
And, just to watch her squirm as the toxins made their way into her system, he used one bit of information that she had given him to play with her mind. "Are you sure your mother is dead? There are tricks, you know. To make you...tick. How are you sure that what you saw was real?"