On the plasma screen, the graphs suddenly disappeared, replaced by a spinning BREAKING NEWS logo. It was replaced a moment later by the face of a TV network woman, with the words SUDDEN OIL SHOCK scrolling across the screen. Arthur couldn’t hear her over the shrieking machine and the whirr and buzz of its arms, but he could guess what she was saying.

The Grotesque’s bizarre machine had somehow sent the price of oil up fifteen percent.

‘What stocks does your father own?’ jeered the Grotesque. It took a piece of paper out of its apron pocket and looked at it. ‘Oh, I know.Music SupaPlanet, down fifty percent!’

Again it spoke a strange word that sent a ripple of pain through Arthur’s joints. The spider-arms stopped at the word, then began a different dance, tracing out their strange formulae in patterns of light.

Arthur shook his head to try and clear the after-effect of the bright sparks and the words. On the second shake, he saw something. A little door at the base of one of the huge paper mill chimneys. A metal inspection hatch that was slightly ajar.

The chimneys go below the surface. That has to be a way down.

He ran towards the hatch, with the Grotesque’s voice echoing all around, even above the shrieking engine.

‘Northern Aquafarms, down twenty-five percent!’

Arthur reached the inspection hatch. As he pulled it open, the shriek of the engine suddenly stopped. He glanced back and saw the Grotesque staring at him malignantly.

‘Go where you will, Master of the Lower House. The Machine merely pauses for want of fuel, and I shall soon supply that!’

Arthur shuddered, bent his head and climbed through the hatch. He was only just inside when the Grotesque shouted something, another word that made Arthur’s teeth and bones ache, and slammed shut the hatch behind him, cutting off all the light.

In the brief moment before the door closed, Arthur saw that the chimney was at least thirty feet in diameter, with well-worn steps that circled around and down. In the total darkness, Arthur descended by feel, careful not to commit his weight to a step until he was sure it was there. Not for the first time, he wished he still had the First Key, for the light it shed and many other reasons.

Finally he reached the bottom. It was slightly flooded, water coming up to Arthur’s ankles. The river was close by here. He was probably below its level, Arthur thought uneasily. It didn’t help to think of the river suddenly breaking in, not here in the absolute darkness.

But there had to be a way out, a way into the House. Didn’t there? Arthur began to think that he had been lured into a trap. Maybe this was just a chimney and he’d been led into it like a complete fool.

Maybe the Grotesque is going to let more water in. Is it already rising?

Arthur began to edge around the walls, feeling with his feet and hands. He was starting to panic, and the cold water was not helping his breathing. He could feel his right lung seizing up, the left labouring hard to make up for its companion’s failings.

His hand touched something sticking out from the wall. Something round, about the size of an apple. Something smooth and soft.Wooden, not brick.

A door handle.

Arthur sighed in relief, and turned it.

The door opened inwards. Arthur stumbled in, tripping over the entrance. His stomach somersaulted as he continued to fall.

Straight down!

Just like the last time he’d entered the House, Arthur was falling slowly – as slow as a plastic bag caught on a summer breeze – through darkness.

But this time he didn’t have the Key to get him out of this strange in-between place that was neither his own world nor the House. He might fall forever and never arrive anywhere . . .

Arthur gritted his teeth and tried to think of something positive. He had held the First Key. He was the Master of the Lower House, even if he’d handed his powers over to a Steward. He felt sure there was some remnant magic in his hands, which had once wielded the Key.

There has to be some residual power.

Arthur thrust out his right hand and imagined the Key still in his fist. A shining Key.

‘Take me to the Front Door!’ he shouted, the words strangely dull and flat. There was no echo in this weird space, no resonance of any kind.

Nothing happened for a few seconds. Then Arthur saw a very pale glow form around his knuckles. It was so dark it took him a little while to work out what it was. The light comforted him, and he tried to concentrate on it, willing it to grow stronger. At the same time, under his breath, he kept repeating his instruction.

‘Take me to the Front Door. Take me to the Front Door . . .’

His wrist clicked as his hand moved away, tugged by an unseen force. He felt the direction of his fall change from straight down into a shallower dive.

‘Take me to the Front Door. Take me to the Front Door. Take me to . . .’

Far off, a tiny light caught Arthur’s eye. It was too far away to be more than a luminous blob, but Arthur felt sure he was headed towards it, that it would grow and grow until it became a huge rectangular shape of blinding light.

It had to be the Front Door of the House.

FIVE

TO ARTHUR’ S CONS IDERABL E relief, the light did grow and it did look exactly like the Front Door. Only this time he was approaching very slowly, so he had enough time to prepare himself for the shock of falling through to the other side – to the green lawn of Doorstop Hill, in the Atrium of the Lower House.

Once he was there, he figured it would be relatively easy to get to Monday’s Dayroom. Arthur wondered if it was called Arthur’s Dayroom now, or TheWill’s Dayroom, or something else completely different. In any case, he would find the Will and Suzy there, and together they would work out what to do about Grim Tuesday and his minions.

Arthur was still thinking about that as he drifted gently towards the Door, when he was unexpectedly thrust forward by a tremendous force. Completely unprepared for what felt like a giant whack in the back, he tumbled end over end and crashed headfirst into the bright rectangle of light.

For an instant Arthur felt like he was being turned inside out, everything twisted in impossible and painful directions. Then he bounced on his feet on the other side and crashed down onto his hands and knees. Jarring pain in both told him he had not landed on soft grass. It was also completely dark, without even the soft glow of the distant ceiling of the Atrium, and certainly no elevator shafts illuminating the scene. Even worse, there was smoke everywhere – thick, cloying smoke that instantly made Arthur’s lungs tighten and constrict.

Before he could begin to feel around or even cough, someone grabbed him by the shoulders and pulled him up and back. Arthur swallowed his cough and instinctively screamed, a scream that was cut off as some kind of fluid enveloped him. He started to choke, thinking that he was in water, but a solid clap on the back stopped that and he realised that whatever the fluid was, it wasn’t water and it wasn’t getting into his throat and nose. A moment later he was out of it and could feel air again. He had passed through some kind of membrane or fluid barrier.

Wherever he was, everything looked extremely blurry and there was too much colour, like he was standing with his nose pressed to a stained-glass window where the colours kept mixing up.

‘Relax and blink a lot,’ instructed whoever was gripping his shoulders – a calm, deep male voice that sounded vaguely familiar. It only took Arthur a second to remember whose it was.

The Lieutenant Keeper of the Front Door.

Arthur blinked madly and tried to relax. As he blinked, the colours settled down and the blurriness eased, at least when he was looking straight ahead. It was still very blurry to either side.

‘Are we inside some sort of multicoloured glass ball?’ Arthur asked after a moment. They certainly were inside something spherical and there was light shining into it, light that kept shifting around and was diffracted into many different colours.

‘We are in a temporary bubble inside the Door itself,’ explained the Lieutenant Keeper. He let go of Arthur, stepped in front of him and saluted. As before, he was wearing a blue uniform coat with one gold epaulette. ‘One that lessens the effect of the Door on mortal minds. Now, we only have a brief respite before you must go through to the Far Reaches –’

‘The Far Reaches?’ exclaimed Arthur in alarm. ‘But I wanted to go to the Atrium of the Lower House.’

‘The Front Door opens on many parts of the House, but the door you entered in the Secondary Realms leads only to the Far Reaches and the Grim’s railway station.’

‘I can’t go there!’

‘You must go there,’ declared the Lieutenant Keeper. ‘You have already gone there. I snatched you back, but I cannot keep you inside the Door for any great length of time. You must go where you are going. That is the Law of the Door.’

‘But . . .’ Arthur struggled to think. ‘Okay, if I have to go to the Far Reaches, can you send a message from me to theWill or Suzy, in the Lower House?’

‘That part of theWill is called Dame Primus now,’ said the Lieutenant Keeper. ‘I am afraid I am not allowed to send unofficial messages to her or anyone else. I can hold a message for someone, but I cannot pass it on unless they inquire whether I have one.’

He unbuttoned part of his coat and reached in to withdraw a watch. It played a haunting melody as he flipped open the case and gravely studied the dial.

‘Two minutes, then I must return you to the Far Reaches.’

‘Can you give me a disguise?’ asked Arthur desperately. The Lieutenant Keeper had helped him before with a shirt and cap, so he didn’t stand out in the Lower House. Arthur would need a disguise even more in Grim Tuesday’s domain.

‘That I can do. I hoped you would ask.’

The Lieutenant Keeper reached out through the glowing walls of the sphere.When he pulled his hand back he held one end of a clothesline. He reeled it in. As the pegs dropped off, various items of clothing fell into Arthur’s lap, including a faded pyjama-like top and pants, a strange hooded cape of some rough material the colour of mud, and a many-times-patched leather apron.

‘Put the work suit on over your clothes,’ instructed the Lieutenant Keeper. ‘You will need layers for warmth. Roll up the cape for later.’

Arthur put on the pyjama-like top and trousers, and then strapped on the apron, which was very heavy leather. As instructed, he rolled up the hooded cape. It was very thick, and difficult to squash down. Arthur didn’t recognise the material.

‘Stabilised mud,’ said the Lieutenant Keeper as Arthur looked down on the rolled-up cape that was a quarter as big as he was. ‘Inexpensive and it offers sufficient protection against the Nothing rain in the Pit. While it lasts.’

‘Nothing rain?’ asked Arthur. He didn’t like the way the Lieutenant Keeper said the Pit either. He remembered that the Atlas had called it a huge sore in the foundation of the House.

‘The Pit is so vast that clouds form partway down and there is constant rain,’ said the Lieutenant Keeper as he reached back out through the barrier and retrieved a pair of wooden clogs stuffed with straw.

‘The rain concentrates the Nothing pollution that pervades the Pit and carries it back down. Hence the name.’

‘But what is the Pit exactly?’ asked Arthur. All he knew from the Atlas’s earlier reference was that it was some sort of giant mine, and a danger to the House.

‘Unfortunately, you will soon see for yourself. I fear you will have difficulty staying out of it. Once in, you should escape as quickly as you can. Now – put on the clogs. Keep your socks. They are not so different as to attract notice.’

Arthur slipped off his comfortable, arch-supported, computer-designed sneakers and put on the straw-stuffed wooden clogs. They felt loose and extremely uncomfortable. When he stood up he couldn’t take a step without his heels lifting out.

‘I can’t even walk in these,’ he protested.

‘All the indentured Denizens wear them,’ said the Lieutenant Keeper. ‘You cannot risk being given away by your footwear. Now, for the smog. It contains minute particles of Nothing, so it wears down Denizens and will almost certainly slay a mortal. Which hand did you hold the First Key in most?’

‘The right,’ said Arthur.

‘Then you must put two fingers from your right hand up your nostrils and your thumb in your mouth while you inhale and recite this small spell: First Key, grant this boon to me, that the air I breathe be pure and safe, and keep from me all harm and scathe.’

‘What?’

The Lieutenant Keeper repeated his instructions and added, ‘You may need to repeat this spell, as it too will be worn down by the smog, and the residual powers of the Key will fade from your flesh. Put on the cape. Do not stay overlong in the Far Reaches, particularly the Pit.’

‘I won’t if I can help it,’ muttered Arthur. ‘I guess I can always get out up the Improbable Stair if I really have to.’

The Lieutenant Keeper shook his head.

‘You mean I can’t use the Stair?’ asked Arthur. He knew the Stair was risky, but at least it had been an option. Like a parachute or a fire escape. Some faint hope of escape from disaster.

‘You would never reach a favourable destination,’ said the Lieutenant Keeper. ‘Not without a Key, or a well-practised guide.’

‘Great,’ said Arthur dolefully. He carefully put his fingers in his nostrils and his thumb in his mouth. It was difficult to say the spell around his thumb, but possible. He felt a tingling in his nose and throat as he said the words, and at the end of the spell, let out an enormous sneeze that rocked him back on his heels.

‘Good!’ declared the Lieutenant Keeper as he quickly consulted his watch again. ‘Now we must return you to your destination. I have done all I can, Arthur Penhaligon, and more than I should. Be brave and take appropriate risks, and you shall prevail.’