Finally he got control of himself. 'Yes, yes, of course,' he said, his voice barely shaking. 'Yes, I mean, that's obvious. Plain as the nose on your face. But... er, have you worked out what else is special about k?' he added, trying to keep any trace of hope out of his voice.
'You mean the fact it's gone mad, sir?'
'Well, I didn't think it was winner of the Ankh-Morpork Mr Sanity Award!' said Vimes.
'I mean they drove it mad, sir. The other golems. They didn't mean to, but it was built-in, sir. They wanted it to do so many things. It was like their... child, I think. All their hopes and dreams. Arid when they found out it'd been killing people... well, that's terrible to a golem. They mustn't kill, and it was their own day doing it—'
'It's not a great idea for people, either.'
'But they'd put all their future in it—'
'You wanted me, Commander?' said Cheery.
'Oh, yes. Is this arsenic?' said Vimes, handing her the packet.
Cheery sniffed at it. 'It could be arsenous acid, sir. I'll have to test it, of course.'
'I thought acids sloshed about in jars,' said Vimes. 'Er ... what's that on your hands?'
'Nail varnish, sir.'
'Nail varnish?'
'Yes, sir.'
'Er... fine, fine. Funny, I thought it would be green.'
'Wouldn't look good on the fingers, sir.'
'I meant the arsenic, Littlebottom.'
'Oh, you can get all sorts of colours of arsenic, sir. The sulphides - that's the ores, sir - can be red or brown or yellow or grey, sir. And then you cook them up with nitre and you get arsenous acid, sir. And a load of nasty smoke, really bad.'
'Dangerous stuff,' said Vimes.
'Not good at all, sir. But useful, sir,' said Cheery. 'Tanners, dyers, painters... It's not just poisoners that've got a use for arsenic.'
'I'm surprised people aren't dropping dead of it all the time,' said Vimes.
'Oh, most of them use golems, sir—'
The words stayed in the air even after Cheery stopped speaking.
Vimes caught Carrot's eye and started to whistle hoarsely under his breath. This is it, he thought. This is where we've filled ourselves up with so many questions that they're starting to overflow and become answers.
He felt more alive than he had for days. The recent excitement still tingled in his veins, kicking his brain into life. It was the sparkle you got with exhaustion, he knew. You were so bone-weary that a shot of adrenalin hit you like a falling troll. They must have it all now. All the bits. The edges, the corners, the whole picture. All there, just waiting to be pieced together...
'These golems,' said Carrot. 'They'd be covered in arsenic, would they?'
'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?'