"It's no diamond!"
"What, then, is it?"
"A common piece of glass not worth a quarter of a farthing."
"What's it all about, then?" said I. "Upon my soul, there's nothing in Euclid to beat it. Glass?"
"A little lump of common glass; a fragment of bull's-eye, perhaps."
"What's he hiding it for?"
"Because," said Captain North, in a soft voice, looking up and around, "he's mad!"
"Just so!" said I. "That I'll swear to now, and I've been suspecting it this fortnight past."
"He's under the spell of some sort of mania," continued the captain; "he believes he's commissioned to present a diamond to the Queen; possibly picked up a bit of stuff in the street that started the delusion, then bought a case for it, and worked out the rest as we know."
"But why does he want to pretend that the stone was stolen from him?"