I don't know who or what it is I suspect, but I am filled with suspicion. It could be about myself and my motives. The 'investigator', churning things up, pulling out all the drawers and emptying their contents. To what purpose? To appease my suspicions!
(Remember, this isn't about me, this is about metaphysics, or what I take the activity of metaphysics to be.)
Let's start by asking something simple. What is a question? A question belongs to a context: polite social interaction, or a procedure of investigation following agreed rules, or the free exchange or barter of information. (I need to look again at Collingwood on questions, answers and presuppositions.) The presuppositions of the very act of your asking me a question include, above all, the idea of collaboration, agreement. You have a right to ask, and the worst that can happen is that I decline to answer, not necessarily because of ignorance.
However, we need another name for the questions raised by metaphysics. The metaphysician interrogates. Interrogation is not polite. Interrogation involves violence, and indeed intends violence. Examples of great interrogators would be Freud, or Marx, or Nietzsche. To interrogate is to seek to unmask. Stanley Cavell in one of his essays (in Must We Mean What We Say?) talks about the danger of unmaskers themselves being unmasked. Once suspicion enters the arena there is no natural place for it to stop.
I am an interrogator, then. But one in the strange position of not knowing exactly who or what to interrogate. I know enough to know that this isn't psychoanalytic or radical political critique (though of course anyone can lay that on me if they are so inclined). I suspect the world. But I already said that. So what next? Well, I have my list of suspects (kind of). It's not very long: myself, and the world. One or other, or both, surely must have something to hide.