Ottershaw noticed Daniel’s surprise. ‘Ah!’ he said with satisfaction. ‘You took me for an eccentric, didn’t you? Not at all. Most practical man. Science doesn’t lie, we merely misunderstand her sometimes. We find what we expect to find, or worse still, what we want to.’
He led the way over to a filing cabinet, produced keys from his pocket, and opened the locked section. He withdrew a file, and from the bottom of the drawer a gun wrapped in muslin. ‘See!’ he said, like a conjurer about to begin a trick. ‘We shall now examine the shell casing very carefully, and see what we have.’ With that, he pulled on cotton gloves, removed the gun from its wrapping, along with the separately wrapped shell casing.
‘What is the file?’ Daniel asked.
‘Why, a picture of the prints we took of Mr Blackwell, so we might compare them with the ones we were hoping to find on the gun, of course.’
‘But we didn’t find any,’ Daniel pointed out.
Ottershaw gave a sharp, wry look. ‘No, dear boy, and this is only of use to us if we find on the casing some that are not Mr Blackwell’s. If, after all, we find some that are, it’s a very different matter indeed. Now, are you sure you wish me to look?’
Daniel thought only for a moment. His decision would be irreversible, and he was gambling with Blackwell’s life. If he was innocent, it was his only chance. If he was guilty, he was lost. If Daniel did nothing, it was time that he faced the fact that he could not save Blackwell. ‘Yes,’ he said. ‘Better be damned for action than inaction.’
Ottershaw gave him a brief, tight smile, his face dramatically lit and appearing out of proportion in the fixed lamplight of the laboratory. Then he turned and began to work in absolute silence, except for the faint click of the metal, as he picked up the casing on a stick and wedged the end of the stick into a vice.
Daniel stared in fascination as Ottershaw opened a box of powder, dipped a brush into it, and then lightly dusted the shell casing, leaving a residue on it. He moved closer and drew in his breath sharply. There were tiny lines forming patterns on the surface of the metal.
Ottershaw breathed out slowly. It was only a faint sigh, but he was clearly on the brink of discovery. ‘Not yet!’ he warned. ‘There are fingerprints, but whose?’
Daniel nearly answered, then realised that Ottershaw was talking to himself. The man’s face was alive with the intensity of exploration. This was his art, his miracle.
Ottershaw ignored Daniel entirely now, absorbed in study through a magnifying glass.
Daniel held his breath.
‘Possible . . .’ Ottershaw said at last. ‘They are like Blackwell’s, but there are differences. Yes, definite differences. See – here.’ He moved back from the table, gesturing towards both the photographs of Blackwell’s prints and the print on the casing. ‘Look – there are whorls . . .’ He pointed with the tip of a small, sharp instrument. ‘Look.’
Daniel peered at it and saw fine lines in almost a circle.
‘See?’ Ottershaw urged.
‘Yes.’
‘And those are Blackwell’s that we took before. See where the thumbs are almost the same?’
‘Yes . . .’
‘Now look at these.’ Ottershaw pointed to the casing and a break in the lines below the whorl. Only a print of a thumb was there, but the lines were at a different angle, and there was a brief break in them: islands. Different! They were not made from the same thumb. He indicated the photograph of the right thumb, and then pointed to another photo. ‘Isn’t the left thumb either,’ he said with conviction. ‘Of course, we don’t know whose it was. Doesn’t matter for this trial if we did. This is cause only for reasonable doubt.’ He looked at Daniel carefully, to be sure he understood.
‘Of course,’ Daniel agreed, but he now had proof that Blackwell was not the murderer.
Ottershaw shook his head. ‘Lot to learn, dear boy. Jurors are twelve ordinary people, not twelve enthusiasts for new adventures of the mind. Sitting still all day trying to concentrate on the arguments going on in front of them is enough adventure for most. They believe what they can understand. Trust me, I’ve tried to explain some finer points of science, and I might as well have saved my breath to cool my porridge. You’ve not only got to be right, you’ve got to be better than the other man. And Sefton is no fool. I know him. He’ll try to make them think your chap’s a trickster, a fraud. And that you are naïve. You won’t win them over just with facts.’ He shook his head as if he had said this many times before, but to no effect.
Daniel felt suddenly deflated. ‘But you can see that that is not Blackwell’s thumbprint!’ he exclaimed.
‘You can see that,’ Ottershaw agreed. ‘But if I don’t want to believe that, then I won’t.’
‘Yes, you will,’ Daniel contradicted immediately.
Ottershaw smiled widely. ‘Yes,’ he conceded. ‘I will. Because Blackwell is a rogue, but I don’t think he’s a killer. And I’d like you to win. I like you. You’re the future, open-minded, willing to learn, eager, and with sense to listen to what you’re told – most of the time. But that isn’t enough to win.’
Daniel was deflated. ‘Then what is?’
‘Make them want to believe you, and then show them why they should. They’ll do it then, and Sefton won’t argue them out of it.’
‘But I’ve only got half a day!’
Ottershaw’s eyes were bright. ‘Then you’ll have to be quick!’