And it wasn't till half an hour later that he suddenly struck the table with his fist.

'Yes,' said he, 'maybe he's mad, but that can't affect it....' Again he didn't say what it couldn't affect.

Of course I'm only giving you an extract of the conversation, but one can understand the sense of it.

You may ask whom you like, they all have the same idea in their heads, though it never entered anyone's head before.

'Yes,' they say, 'he's mad; he's very clever, but perhaps he's mad too.'" Stepan Trofimovitch sat pondering, and thought intently.
"And how does Lebyadkin know ?" "Do you mind inquiring about that of Alexey Nilitch, who has just called me a spy?
I'm a spy, yet I don't know, but Alexey Nilitch knows all the ins and outs of it, and holds his tongue." "I know nothing about it, or hardly anything," answered the engineer with the same irritation.