It's not long before Richard's own mental processes are, for lack of a better word, replaced with Jim's, and it's a vaguely frightening experience. Unfamiliar thoughts and emotions, and no reference point to use as an anchor.

He actually changes his mind. If this is what it's like to be a genius, to be constantly suffocated by your own brain, Richard doesn't want it. He already wants to turn everything off and go back to the muffled silence of contentment, but he can't. It doesn't stop. If anything, it gets louder.

No wonder Mr Holmes shoots walls. It's enough to make anyone go mad.