Finding their way about the Neanderthal complex was a nightmare. Any expectations about dwellings, construction or simply places where people lived were defeated by the haphazard way the lair of the Neanderthals had been put together. Some levels eschewed straight lines entirely, with corridors curving back and forth, even twisting back on themselves. Other levels were clinical in their straightness and the transition between these sections was breathtaking.

There were no standards. Ceiling heights, widths of corridors, wall colours, shape of doors, all were random or up for argument. Even the notion of level floors was arguable, it seemed, with some parts undulating like sand dunes, for no apparent reason. It was as if the entire place were put together by teams of builders who were using entirely different plans.

The levels were connected by far more lifts and stairs than were needed. They were situated right around the perimeter of the levels and presented a swashbuckling variety of means of locomotion: hydraulic lifts, pneumatic lifts and one that Evadne concluded was an electrical traction lift.

One advantage of all this was the potential for hiding places. They found many abandoned rooms, as if the population had been much greater in past times, and some stairwells were dead ends – useful as a temporary refuge, but appalling as means of access.

In order to catch their breath and take stock, they’d secreted themselves in one of the vacant suites, a chamber set in solid rock. The walls were so rough that mounds of rubble were still strewn about, behind which Kingsley and Evadne sat – but not before Evadne had confirmed that the room had three doors leading to other parts of the complex. She wasn’t about to be trapped in a room with no exit. Kingsley thought it an excellent idea, especially since the main door was broken and couldn’t be shut completely.

‘On the whole,’ Evadne panted, ‘I’d rather be at home.’

Crouched next to her, behind something that could have been either a miniature forge or a work of modern art, Kingsley struggled to reply.

His wild self was pressing hard and threatening to burst out.

‘Somewhere far from here would do,’ he said through gritted teeth.

Four Neanderthals ambled past, chatting. They carried tool chests, and one had a flaming blowtorch in one hand. His friends jeered when he gestured grandly and nearly set his own beard on fire.

‘I have an idea,’ Kingsley said.

‘That’s timely, because I’m baffled. This place is larger than I thought.’

‘If we’re trying to find a workshop, why not follow workers?’

‘That, sir, is a fine piece of reasoning.’

‘Glad to be of assistance.’

‘Interesting and useful,’ she mused. Then she pursed her lips. ‘Laurence would like to meet you, I’m sure. He’s interesting and useful as well.’

‘Laurence? Don’t you mean Clarence?’ Kingsley climbed to his feet and slapped dust from his trousers.

‘Clarence? Of course. Just testing how alert you are.’

The Neanderthal workers were loud, making them easy to follow. The task needed stealth, however, which appealed to Kingsley’s animal side.

By watching the lifts the Neanderthal workers used and timing their approach carefully so that no-one was waiting in the awkwardly shaped cubicle where the lift arrived, Kingsley and Evadne were eventually able to make their way down to the industrial level of the Neanderthals’ lair, deep under the ground.

The choice of doors was made easier by the stream of Neanderthals leaving and entering the far door, from which the sounds of machinery and construction also emerged whenever it was open. The nearer door was closed, but promised proximity to the site of Neanderthal activity. A few seconds’ work on the lock and they were inside.

They emerged into a high-ceilinged workshop. Twenty yards away was the far wall, which had a single door. Overhead were festoons of electrical cables and pipes, while the steam ducts rattled on the wall to their right, near the floor. Benches and tool racks lined the walls to their left, right and opposite, only interrupted by a glass-fronted cabinet that was alive with red light. Inside were dozens of tiny glass vials that Kingsley had seen elsewhere.

In the middle of the room, however, was the feature that gave Kingsley pause and prompted a gasp of admiration from Evadne.

A round raised area displayed something that could be called a machine, if one were using language to reduce rather than describe. It reached forty or fifty feet into the air. To Kingsley’s eye it looked like a descendant of a funfair helter-skelter but with embellishments and additions that defied comprehension. A disc at the apex anchored thousands of golden wires that hung to the ground and nearly obscured the spiral walkway around the inner tower. When the wires rippled in the slight draught, they emitted a sweet, gentle ringing sound.

Directly in front of the machine was a brass pedestal. The base was wrought to look like a stalagmite. The panel on the top was the size of a tea tray and was a riot of crystal and glass.

Evadne took two steps forward and tried to look at the machine and the pedestal at the same time. She clasped her hands and touched them to her chin. ‘Can you lock the door?’ she asked softly. ‘And do something to the lift so we’re not disturbed? I want to look at this. No.’ She shook her head. ‘I need to look at it.’

‘It’s the time machine?’

‘It’s beautiful.’

Working out a way to bar the lift took some time. The controls inside were basic in the extreme and impervious to tampering. He settled for jamming the door open with a length of pipe he found on one of the benches.

He was on his way to lock the workroom door when the tools on one of the benches took his eye. Impressed by the quality of the workmanship, he picked up a beautifully finished pipe cutter – and a number of things happened one after the other.

Firstly, Kingsley found himself thinking that he hadn’t known that Evadne was a whistler, then a gravelly voice that wasn’t Evadne’s cried out, ‘Who are you?’ only to be followed by a rather ominous click, a hiss, and a snap, that led to an even more ominous heavy bodily thump.

Kingsley was halfway around the glittering machine before he knew it to find a dismayed Evadne pocketing her dart gun and running to crouch beside a white-coated female Neanderthal who was stretched out on the floor.

‘I’m sorry,’ Evadne said, but whether to him or to the young Neanderthal woman he didn’t know. They made a contrasting pair, with the ruddy features and bright red hair of the stocky Neanderthal against Evadne’s snow-white countenance. She looked up. ‘I wasn’t thinking. I should have questioned her before shooting.’

‘I hadn’t managed to lock the door yet. Stupid of me,’ Kingsley admitted. ‘What’s that in her hand?’

Evadne uncurled the fingers. Gently, she removed a glass capsule. Its red glow suffused her features. ‘Ah.’

She touched her spectacles. Immediately they became slightly purple. She cocked her head. ‘I thought so. Phlogiston. Remarkable.’

‘More over there,’ Kingsley said, pointing at the glass cabinet.

Evadne stood. ‘I think I have a way to disrupt their plans for quite some time.’

Undoing her satchel as she went, Evadne hurried to the cabinet. The red light from it touched her features as she stood for a moment, studying the racks inside. ‘There’s enough phlogiston here to make a Demimonder a king.’

With an abrupt but graceful motion, Evadne swept a hand along the racks, tumbling the vials into the open satchel until she’d emptied the entire cabinet. She buckled it up and patted it. ‘This will set them back, at least.’

‘Will it give us enough time to get help?’

Evadne put a finger to her lips and bounced it once or twice. ‘Why don’t you go and make sure the door is locked this time?’

The door didn’t take much effort, despite the oddity of the spring plate mechanism. When Kingsley rounded the machine, Evadne was studying the brass pedestal. She glanced at him, looked back to the panel, then held up a phlogiston vial. ‘I think this goes . . . here.’

Before Kingsley could protest, she slid the vial into an opening on the face of the panel. For a moment, nothing happened and Kingsley was relieved. Then a rapid series of rattles came from the machine and overhead a bank of lights came alive. They made the golden wires even more radiant and the whole machine shimmered. Now that Kingsley was closer he could see that the wires weren’t attached at the bottom. They hung free, making the whole enclosure more of a curtain than a cage.

If we’re trying to be furtive, he thought, we’re not going about it the right way. He ran his fingers through his hair with exasperation. ‘What on earth are you doing?’

‘I’m trying to work out if this is a time machine or not.’ She scowled at the panel. ‘And, if so, how it’s calibrated.’

‘By starting it up?’

‘With all the noise next door, I’m sure no-one will notice.’

‘I’m not.’

‘Oh, Kingsley, I couldn’t not try it.’ Her eyes were bright. ‘It’s magnificent!’

‘We don’t have time for this.’

‘It’s just a test. A very careful, sensible test.’ Her hand rested on the panel. Her forefinger bounced up and down, while the others remained still. ‘I’d say that most of these controls are for settings. I wonder if they keep specifications anywhere.’

Kingsley shook his head. ‘We’re supposed to be destroying it, not worshipping it.’

Evadne looked stricken. ‘But it’s so wonderful! We could learn so much!’ Then she gathered herself. ‘Of course. I’m sorry.’

At that moment, pounding came from the nearest door. Kingsley jumped with what he hoped was aplomb. He cleared his throat. ‘Are you finished?’

A hum rose from the golden curtain. The sharp smell of ozone made Kingsley wrinkle his nose. It was like being near an electrical substation in the rain. A series of sharp snaps ran around the upper rim of the machine. Sparks curved into the air and immediately flew upward before disappearing into the mesh above the gantry.

The pounding on the doors became hammering, with angry shouts as an underscore. ‘Now,’ Evadne said, ‘you’re the escapologist – what’s the best way out of this pickle?’

Kingsley rapidly turned over the de-pickling options, opted for the lift, but discarded this when the door of the lift edged back, then rammed forward, dislodging the iron bar he’d put in place.

The lift disappeared upward.

Now, he thought. That’s unhelpful. ‘How many darts do you have?’

‘A dozen.’

‘And you’re a good shot?’

‘With these spectacles? I’m a marksman. Markswoman. I’m unerring.’

‘Right. We climb to the top of that machine. You keep shooting until they stop coming. Then we get out through the doorway, using your sabre and my knife.’

‘That’s the best you can come up with?’

‘It’s better than being eaten.’

‘All it does is put off being eaten while making them angrier.’

‘True.’ Kingsley looked around, hoping to spot a secret door he’d missed seeing earlier. ‘The Basic Principles of Escapology.’

‘I know. Stay calm, take your time. You’ve told me.’

‘There’s one I haven’t shared with you.’ He took her hand. ‘Come on.’

He led her up onto the platform. The time machine was rotating. An almost musical hum was coming from deep inside it.

Evadne looked at it, then at Kingsley. ‘You want to use the time machine?’

‘One of the most important Basic Principles of Escapology: when there’s only one way out, use it.’