murky looking water and illuminated by a black-lamp that hummed quietly. It looked like the specs floating around in there were glowing.
'What subject did you say he was teaching?' I asked.
'I didn't. He teaches modern history, we met at an academic convention.'
'This doesn't look like history to me.'
'His research follows a rather wider remit. Gregor is a scientist and a magician — he's into all sorts of esoteric ideas and sees no distinction between science, philosophy and magic. Last time I was here he was trying to show me a perpetual motion machine.'
'That's not possible,' I stated with some certainty.
'You're a fine one to talk about what is and is not possible,' she reminded me. 'Gregor, are you here?'
'Can't you see I'm busy?' A voice came from a smaller office attached to the lab. 'The tutorials have all been rescheduled — new dates have been sent out by email. Check your spam filter — it's probably in the spam folder.'
'Gregor, I'm not one of your students,' she called through to the office.
'Then what are you doing in my…' His face appeared around the door. 'Veronica! How absolutely delightful to see you. How long have you been there?'
A barrel chested, moustached grandee of a man swept out of the office and picked up Blackbird in a bear-hug embrace, kissing both her cheeks noisily twice.
'Mmmwa! Mmmwa! It is fantastic you are here. I have something to show you. Have you heard of wave energy stimulation? Do you have a bodyguard now?'
'Gregor, this is Niall. He's helping me with some research and we wanted to pick your brains.'
He turned to me and extended a hand. 'Gregor Leyonavich, at your service.' He wore generous sideburns which almost connected with his moustache. Taking his hand, I shook it firmly and slowly.
Gregor smiled. 'Sword callous, right hand, a long weapon and heavy by the feel of it, not a practice weapon and not one of those toys, those lightweight foil things. I was joking about the bodyguard, Blackbird, but maybe this is not a funny joke?'
I glanced at Blackbird.
'Sherlock Holmes is one of Gregor's heroes. He observes everyone and everything,' she said.
'Sherlock Holmes never existed. He was a fictional character,' I pointed out.
'Quite so, but in his genius, Conan Doyle invented the ultimate rationalist,' said Gregor, 'sceptical about everything but assuming nothing, evaluating all possible alternatives. You have muscle underneath that jacket, which means you work at it. Your weight is balanced towards your toes, so you have been trained. You are no amateur, I think. Your right shoulder is higher than your left, which implies a bias to one side, so not a master swordsman, but very competent. Not often you come across a trained swordsman these days. But when you have eliminated the impossible, whatever you have left, no matter how unlikely, is the truth.'
'In my experience the truth is in the eye of the beholder,' I said.
'Well said, my friend, but without truth we cannot have beauty, which brings me back to the delightful Veronica. My dear, they told me you had sold your soul to the Americans.'
'I'm back for a little while,' said Blackbird, 'but I am not advertising my presence. I have no wish to get sucked back into academic rivalry.'
'An overrated occupation at best,' agreed Gregor. 'Come, let me show you my wave energy demonstrator.' He gestured across the lab to a machine in the corner. 'One day, machines like this will power entire cities.'
He went to a bank of switches and relays on the wall and clicked on a pair of large red switches. Boxes began to hum and lights flashed on displays. A laptop computer stopped showing screensaver pictures and began displaying a graph with flat-line red and green readings.
'The matter we wanted to discuss…' said Blackbird.
'A moment only, I promise,' interrupted Gregor. 'This is impressive; wait and see.'
An orange indicator turned to green and Gregor threw a switch with a flourish. A laser emitted a blue-white beam which was split by a half-silvered mirror and bounced around various prisms before hitting another pair of prisms which brought the beams together again into a single beam aimed at a detector. Gregor carefully adjusted an instrument that was receiving the beam.
The prisms and the mirror were inscribed with odd symbols — It made me wonder what his native language was. Something Eastern European by the sound of it.
'Watch the display,' he said. 'The red one shows total energy input while the blue one shows the energy released.'
The lines on the graph started to climb until they levelled off about half-way up the screen, the red line on top indicating that energy input exceeded energy released by about a third again. A digital read-out measured the difference at just over minus twenty-seven percent.
'This is the default state. The gaps between the lines indicate the energy used by the system,' he explained.
'Gregor, this isn't what we came to talk to you about,' said Blackbird.
Gregor ignored her, intent on the rig. 'Now,' he said, 'I'm using microwave transmitters to introduce harmonics into the beams.'
He turned a dial and the blue line began to climb towards the red.
'That's just increasing the energy input to the system,' I pointed out.
'It would be if the beams were absorbing energy from the microwaves,' he argued, 'but that's not what's happening. The energy in the microwaves is all accounted for in the measurements. There's no direct transference, or rather there is, but it's already been subtracted from the read-out.'
The red line rose slowly as he increased the input, but the blue line rose faster, until it passed the red line and stabilised above it. The read-out said plus eleven point two percent.
'You must have an energy source that's not accounted for,' I stated.
Blackbird kicked my ankle hard enough to get my attention. 'What Niall meant to say is that we have a question we'd like your view on.'
'No,' he ignored Blackbird again. 'It's all in the measurements. What's more, you can increase the input to the laser, and the percentage yield stays constant without increasing the microwave input.' He adjusted the input to the laser and the blue line climbed even further away from the red one.
'That's not possible.' I was sure I was right. 'Energy has to come from somewhere.'
'Niall. You're only encouraging him,' said Blackbird.
'You're missing something, surely?' The experiment was interesting, but there had to be a source for the increased energy. It couldn't come from nowhere. It was a long time since I'd done any physics, but it was a basic law of the universe that you don't get something for nothing.
'That's what I thought,' said Gregor, 'but I'm damned if I can find it.' He flipped the master switch and the system clicked off. The lines on the laptop dropped to nothing. 'What was it you wanted to ask me?'
Blackbird glared at me, but I shrugged. He was clearly enthusiastic about his experiment. What harm could it do to let him demonstrate it?
'A couple of items were stolen recently,' she explained, 'and I thought you might be able to tell us what their significance might be.'
'What sort of items?'
'A key from an Anglo-Saxon burial mound and a tail feather from a raven,' I told him.
His eyebrows lifted. 'Not the usual sort of thing,' he stated. 'What makes you think these thefts are related?'
'They were stolen at the same time,' said Blackbird, 'from the same place.'
'The Tower of London?' said Gregor.
'How did you know that?' I asked.
'Give me another instance where ravens and keys are kept in the same place,' he said. 'I cannot think of one. Besides, your question answered mine.'
'What do you think, Gregor? What are they doing with these things?' asked Blackbird.
'You haven't mentioned jewels, so I assume they didn't succeed in stealing those?'
'As far as we can tell,' I said, 'they didn't even try to steal them. They used the jewels as a distraction but
