"Yes," Doctor nods. A vague answer to start with. "It can be shocking the first time. I apologize."

Greg might then feel a sensation in his mind as if someone is knocking on the metaphorical front door of his head. There's a faint voice, Doctor's, speaking muffled as if he has his hand over his mouth (which he doesn't, he's simply staring at Greg with his mouth shut).

Telepathy. As it turns out I have a very basic form of telepathy.