Doctor Who_ Camera Obscura - Lloyd Rose [48]
It had been the Doctor, she thought now, still picking tensely at the loose thread. It had. He had reached out somehow and hurt Sabbath. Impulsively, she got to her feet and left her room. On the broad staircase, she stopped, gripping the banister, at the sound of voices from the study. She recognised them both: Sabbath’s resonant bass, and the Doctor’s tenor, strident now in anger. She rushed down the stairs and flung open the door.
The Doctor spun around. His eyes were a hot, dark blue, like dying flames. ‘Call off your pet psychopath!’ he spat.
She glanced to Sabbath, who was in his chair by the cold Fireplace. He nodded at her calmly. After a last, assessing look at the Doctor, she stepped back out of the room, pulling the door to.
* * *
The Doctor wheeled again to face Sabbath. ‘She killed Octave for you.’
‘Of course.’
‘Listen to me, you fool,’ said the Doctor, pacing softly towards him. ‘You’ve murdered our only lead.’
‘I don’t think you understand the situation,’ said Sabbath, unperturbed. ‘This isn’t some mystery novel, with leads and clues. These anomalies incorporate the time disruptions in their very flesh. They have to be destroyed.’
‘I don’t think you understand,’ said the Doctor in a voice like velvet. ‘We’re dealing with a time machine.’
Sabbath sat up. ‘What?’
‘The source and sustainer of these temporal peculiarities is a time machine.’
‘None of the readings indicates the presence of anything that powerful.’
‘It’s a machine, you know. It can be turned off.’
‘How can you be certain?’
‘Because I know,’ the Doctor said furiously. ‘I recognise the technique.’
‘What is it?’
The Doctor began to pace. ‘You’re familiar with optical interferometry, in which light waves are broken up and recombined for a clearer image.’
‘Of course.’
‘Temporal interferometry does the same thing with time.’
‘You’ve seen this?’
‘Somewhere,’ said the Doctor bitterly, still pacing. ‘At some time. The circumstances elude me, but I certainly know the technology. As a functional method of time travel, it proved to be a dead end.’
‘That must be why I haven’t heard of it.’
‘No doubt,’ said the Doctor drily. ‘The basic idea was intriguing. Get a focus on a temporal co-ordinate in the past or future, break up the signals, and recombine them inside the machine.’
‘Rather than travelling to the time period, you brought it to you.’
‘And then just walked into it. Rather elegant, really.’
‘And it worked?’
‘It could work. But the technique was very delicate and complicated – a lot of moving parts, so to speak. Absurdly easy to get wrong. At the end of the day, impractical. Use it under less than precise physical circumstances – the wrong gravity, for example – and you had something that might run time through the equivalent of a meat grinder.’
‘But the power,’ said Sabbath softly. ‘The reach of such an instrument.’
‘Oh yes, extraordinary.’ The Doctor took a turn around the desk. ‘Powerful enough to collapse timelines together if you happened to have some sort of megalomaniacal interest in engineering on a cosmic scale. But if the purpose was to develop usable, reliable time travel, temporal interferometry... When it went wrong it could, at the worst, tear up time itself, and at the least –’
‘– it might fracture the time traveller.’
‘Exactly.’
‘Octave had been in such a machine.’
‘That’s right.’ The Doctor stopped pacing. ‘Wouldn’t it be nice if we could ask him about it? Especially as, any day now, it might get switched on again and chew up the continuum.’
Sabbath shrugged. ‘I was working with the information I had at hand.’
‘Well, you didn’t have enough, did you?’
‘As it turns out, no. Your being so emotional about it can’t change anything.’
‘I’m not emotional – and by the