Mars here with character number four! Hands up, who's seen Inception by now? Ahem.
I don't want to spoil it for anyone, so, quick and dirty version is that this here is Arthur. He's ex-special ops and thinks everything is a dream. Or maybe he's awake, but he can't tell because he lost the loaded die that told him what was what. Yes. Yes I know. Strange boy.
He's addicted to incredibly strong and, let's face it, incredibly illegal sedatives. He still needs to be sedated, but the hospital stuff just don't cut it, probs. His reactions when not sedated are severe and result in hypersensitivity and extreme paranoia. Also if you're tipping back your chair, he will probably knock it over. He's just trying to wake you up. You should thank him.