Sir William raised his finger. ‘Not true,’ he insisted. ‘We have one hour, or slightly less. But that in itself proves that you are right, young man. They are watching, they must be to know when this was delivered. Watching and waiting.’
‘Which leaves us less than an hour, then,’ Liz said.
‘Well,’ Sir William continued, ‘we do have something he evidently wants very badly indeed. So the question is, does he want the slip of paper for himself, or does he want to prevent us having it?’
‘But neither makes sense,’ George said in frustration.
‘On the face of it that would indeed seem to be the case. So I can only assume we are still missing something here. Something important. Something that this paper means or would convey to Lorimore which we have so far failed to discern.’
Liz nodded. ‘And either he wants to know what that is, or he wants us to surrender the paper before we manage to work it out.’
‘Or both,’ George added. ‘But what can it be?’
‘I was about to run some tests on this paper.’ Sir William was examining the scrap again, as he had done an hour earlier. ‘It is possible that it was this that prompted Berry to reveal himself and try to steal it. Or, of course, it may be simply that he saw an opportunity.’
‘What tests did you have in mind?’ George wondered.
‘It seemed rather tenuous and unlikely at the time, but I did wonder if Glick had perhaps written another version of events on the same diary pages, but in invisible ink.’
‘Invisible ink, is that possible?’ Liz asked in astonishment.
‘My father showed me, when I was a boy,’ George remembered, ‘how to write using lemon juice instead of ink. It dried so you couldn’t see it.’
Sir William nodded enthusiastically. ‘Citric acid, a very useful substance. It does as you say dry invisibly. Then the application of heat, from a smoothing iron or some such, will cause the writing to appear in a dark brown form.’
‘We used to toast pages of invisible writing in front of the fire,’ George said quietly. He had a dreamy expression as he stared back fondly into the past.
‘I assume there are other forms that invisible ink can take,’ Liz said.
‘Oh indeed yes, my dear,’ Sir William agreed.
‘What’s wrong with lemon juice?’ George asked.
‘Just that this paper has already been subjected to considerable heat,’ Liz told him. ‘And there is no evidence of hidden writing having appeared.’
‘Oh,’ George said, recalling the fire. ‘Yes.’
‘But we are agreed on the general principle, are we not?’ Sir William said. ‘In some manner, this paper is more than it seems. And because of that, either because Lorimore wishes to know its secrets or because he is desperate for us not to learn them, either way we must at all costs keep hold of it. Are we agreed?’
The others nodded. It did seem the only option.
‘It does at least give us a position of some strength to bargain from,’ Sir William added.
Liz agreed: ‘Give up this paper, and we give up everything.’
‘Splendid.’ Sir William rubbed his hands together in delight as if the whole matter was now completely sorted out. ‘Well, I’ll get on with testing this piece of paper in any and every way I can think of.’
Forty-five minutes later, George and Liz had tired of watching Sir William busying himself with the scrap of paper. Every few minutes they glanced at the clock. Now it was nearly time — the hour that Lorimore had given them was almost gone.
‘I’d better go and get Eddie,’ George said. He had warned the boy what Lorimore had said, and Eddie had agreed they would be best advised to stay put.
‘We can defend ourselves here,’ Sir William had told George. ‘And soon, when morning comes and the staff begin to arrive, he’ll have to call off his thugs or someone’ll call the police.’
Liz went with George and together they joined Eddie on the steps outside the Museum, peering into the foggy night.
‘I can’t see more than about six feet in front of me,’ she said.
‘You hear things,’ Eddie told her. ‘Cabs, people shouting, and stuff.’
‘We might as well go back to Sir William and look for somewhere to hide,’ George said.
‘I doubt he’ll leave his precious collection,’ Liz remarked.
But Eddie was waving at her to be quiet. ‘Listen,’ he hissed.
A moment later, George could hear it too. Carriages. Several of them, judging by the clop of so many horses’ hooves and the rattle of the wheels over the cobbles. It was muffled by the fog, but the sound was clear enough.
‘Inside!’ George said quickly.
The fog seemed to have crept inside the building itself. It hung like smoke in the foyer, where Sir William now stood waiting. He was holding the slip of paper saved from Glick’s burnt diary.
‘Nothing,’ he proclaimed, as soon as Eddie and the others were inside.
George slammed the door shut, sliding heavy bolts into place and turning a large key in the lock.
‘I have tried everything I can think of. Nothing.’ Sir William nodded towards the closed door. ‘Is that really necessary?’
‘Yes,’ George said simply.
‘Lorimore is here,’ Liz explained.
‘And it sounds like he’s bringing Blade and his mates,’ Eddie added.
Sir William raised an eyebrow but seemed otherwise unimpressed. He glanced down at the paper in his hand. ‘Perhaps I have missed something then.’
There was a loud crack from the door behind them. The wood shifted visibly in the frame, creaking as something large and heavy collided with it. A moment’s pause, then another, louder crack.
‘I don’t think that’s going to hold for terribly long, you know,’ Sir William observed just before the third crack of splintering wood. ‘Let’s get back to the laboratory.’ He turned and led the way briskly across the foyer and out into the Great Court.
‘Will we be safe there?’ Liz asked. ‘Shouldn’t we get out the back door or something?’
‘As safe as anywhere, my dear. Lorimore is likely to have all the exits watched. At least we know the territory. Come on.’
Behind them the door was already splintering apart.
They worked hurriedly to barricade the laboratory. Together they managed to drag the heavy workbench across the door. Eddie retrieved his smooth stone from the work top and stuffed it into his pocket.
‘You realise that there’s no other way out of here,’ George said. ‘If they find us, we’re trapped.’
‘We’ll be trapped soon enough wherever we go,’ Sir William said. ‘Our only chance is to bargain. And in here we can bargain, I hope, from a position of strength. We have the paper from the diary, and we have the means to analyse it — and to destroy it if need be. And now, thanks to our visit to his foundry and the time I have had to ponder this in the last hour, we have a good idea of what Lorimore is up to. More or less.’
‘And what is he up to. More or less?’ Liz asked.
Sir William was filling glass flasks and beakers from a tap over a small sink at the back of the room. ‘Help me stopper these up, will you. I’d like an impressive collection ready for when the time comes.’ He had taken off his jacket and rolled up the sleeves of his shirt. Satisfied that Eddie and George were able to put the rubber stoppers into the flasks and cover the beakers with glass lids, he turned to Liz.
‘Lorimore has coupled his fascination with modern technology with his love of fossils and dinosaur discoveries. His plan, it would seem, is to create a dinosaur for the modern age. A work animal that has the strength and power of the dinosaurs, the reliability and stamina of British steam technology, and the intelligence and intuition of humans. Although I think he has some way of regulating the brains of his subjects …’ Sir William paused, then corrected himself. ‘Or rather, his victims. I believe from Albert Wilkes’s behaviour that so far complete control of the individual has eluded him. He can either leave the reasoning faculties intact, along with their free will, or he can assume control — as he does with that monster — but at the cost of any individual thought and initiative.’