'Could be, sir. I saw one at the Alchemists' Guild building in Quirm and, hah, it'd even got arsenic plated on its hands, sir, on account of stirring crucibles with its fingers...'
'They don't feel heat/ said Vimes.
'Or pain,' said Carrot.
'That's right,' said Cheery. She looked uncertainly from one to the other.
'You can't poison them,' said Vimes.
'And they'll obey orders,' said Carrot. 'Without speaking.'
'Golems do all the really mucky jobs,' said Vimes.
'You could have mentioned this before, Cheery,' said Carrot.
'Well, you know, sir ... Golems are just there, sir. No one notices golems.'
'Grease under his fingernails,' said Vimes, to the room in general. 'The old man scratched at his murderer. Grease under his fingernails. With arsenic in it.'
He looked down at the notebook, still on his desk. It's there, he thought. Something we haven't seen. But we've looked everywhere. So we've seen the answer and haven't seen that it is the answer. And if we don't see it now, at this moment, we'll never see it at all...
'No offence, sir, but that's probably not a help,' said Cheery's voice somewhere in the distance. 'So many of the trades that use arsenic involve some kind of grease.'
Something we don't see, thought Vimes. Something invisible. No, it wouldn't have to be invisible. Something we don't see because it's always there. Something that strikes in the night...
And there it was.
He blinked. The glittering stars of exhaustion were causing his mind to think oddly. Well, thinking rationally hadn't worked.
'No one move,' he said. He held up a hand for silence. There it is,' he said softly. There. On my desk. You see it?'
'What, sir?' said Carrot.
'You mean you haven't worked it out?' said Vimes.
'What, sir?'
'The thing that's poisoning his lordship. There it is ... on the desk. See?'
'Your notebook?'
'No!'
'He drinks Bearhugger's whisky?' said Cheery.
'I doubt it,' said Vimes.
'The blotter?' said Carrot. 'Poisoned pens? A packet of Pantweeds?'
'Where're they?' said Vimes, patting his pockets.
'Just sticking out from under the letters in the In Tray, sir,' said Carrot. He added reproachfully, 'You know, sir, the ones you don't answer.'
Vimes picked up the packet and extracted another cigar. Thanks,' he said. 'Hah! I didn't ask Mildred Easy what else she took! But of course they're a servant's little bonus, too! And old Mrs Easy was a seamstress, a proper seamstress! And this is autumn! Killed by the nights drawing in! See?'
Carrot crouched down and looked at the surface of the desk. 'Can't see it myself, sir,' he said.
'Of course you can't,' said Vimes. 'Because there's nothing to see. You can't see it. That's how you can tell it's there. If it wasn't there you'd soon see it!' He gave a huge manic grin. 'Only you wouldn't! See?'