‘Lord Arthur, I presume,’ husked the Rat. ‘Dartbristle, at your service.’
‘Good to meet you,’ said Arthur. ‘This is my friend Suzy.’
‘General Suzy Turquoise Blue if you don’t mind,’ sniffed Suzy.
‘Welcome to the Upper House, General,’ said Dartbristle. ‘Up ahead, we need to heave her around to the left. Hurry now.’
The walkway met another broader walkway at a T-intersection. Manhandling the trolley around without it – or them – falling off the edge was no easy task, but they got it turned and were able to push the Nebuchadnezzar faster once they were in the clear.
Dartbristle kept looking behind them, so Arthur looked too, but all he could see was the thick, grey smoke, with occasional eddies of thicker, blacker smoke coiling up through it. He was no longer surprised that the smoke had no effect upon him. In fact, he even quite liked the smell, though he knew that his old human lungs would have quickly failed in the toxic atmosphere.
‘What are you looking for?’ Arthur asked after they had pushed the bottle several hundred feet and there was nothing to see ahead or behind except more of the platform and more of the smoke.
‘Ratcatcher Automatons,’ said Dartbristle. ‘The sorcerers know when the Nebuchadnezzar fires up – least they know there’s serious sorcery afoot – but it takes ’em a minute or two to plot where it occurred. Since we’re under the floor, they don’t come down here themselves. They send Ratcatchers. But I reckon we might have got away fast enough. Lubricant store’s just ahead, in the bulwark rock.’
‘We’re under the floor of the Upper House?’ asked Arthur.
‘Yep.’ Dartbristle moved around to the front of the bottle and slowed it down as they came up to a sheer and apparently solid rock face of grimy yellow stone that was shot through with barely visible veins of a glowing purple metal. ‘We’re in the bulwark between the Middle and the Upper House. Saturday had a bit of the top part of it burrowed out to put in all her steam engines, chain gear, and so on. Where is that bell push?’
The Rat began pressing different protuberances of rock, but none of them moved in the slightest.
‘Curse the thing, always moving around. You’d think it was made by a practical joker!’ Dartbristle griped.
‘There’s something behind us,’ said Suzy. ‘I saw something go under the walkway.’
‘Ratcatcher!’ hissed Dartbristle. He reached under the Nebuchadnezzar and drew out three long curved knives from the trolley, handing one to Suzy and one to Arthur. ‘They’re armoured, so you need to get them in the red glowing bit right on the front of their head. I suppose it’s an eye or something like it. But watch out for its nippers. And the feelers – they’re like the tentacles of a Blackwater squid.’
He spoke quickly and unhooked the mask from his face so it dangled under his mouth, allowing him to see better. His deep black eyes moved rapidly from side to side, and his nose twitched as he tried to smell the approaching enemy. Suddenly he started forward and raised his knife.
‘Where is—’ Suzy started to say, when all of a sudden the Ratcatcher Automaton sprang out from under the walkway. Darting forward in a flash of steely plates and accompanied by a sound like the soft chink of coins in a leather purse, the twelve-foot-long, two-foot-wide, metallic praying mantis opened its huge claws and nipped at Dartbristle. At the same time, its impossibly long, razor-edged feelers whipped at Arthur and Suzy.
Dartbristle ducked under and around one set of pincers and heaved on the joint, pushing the automaton’s left claw into its right, whereupon they gripped each other tightly. Suzy jumped back from a feeler. It cut her across the chest and tried to wrap itself around her neck to cut her head off, but she blocked it with her knife and slid under the Nebuchadnezzar trolley.
Arthur instinctively parried with his knife and twisted it to trap the feeler. Then, without thinking, he grabbed it and heaved. The razor edges cut his hand, which hurt, but he also managed to pull the feeler entirely out of the Ratcatcher’s head, which caused a great fizz of sparks to jet out like a firework.
‘Get the red eye!’ shouted Dartbristle. ‘While the claws are locked!’
Arthur ran forward. The automaton’s remaining feeler whipped at his legs, but he jumped over it, leaping so high that he landed on the Ratcatcher’s back. The automaton immediately threw itself backwards, but he gripped it around its triangular head and plunged his knife deep into the red orb at the head’s centre. The little bag that held the Fifth Key knocked against the Ratcatcher’s metal overlapping metal plates as Arthur stabbed the automaton several more times, before at last it gave a high-pitched, almost electronic squeal and slowly collapsed to the walkway, its rear legs hanging over the edge.