‘Yes,’ someone else called from further off. ‘I’m getting something now. We’ve regained radio contact.’ There was a pause. ‘No, lost it again.’

The brass exchanged glances at this news, and both checked their watches. Hepton couldn’t believe what he was seeing. They seemed to be worrying about the time. All the while, a billion pounds’ worth of high-tech was whizzing about blindly, or crashing towards earth, and they were worrying about the time.

‘Are you sure you had it?’ yelled Fagin.

‘Yes, sir.’

‘Well then, get it back!’

‘Trying.’

Despite the adrenaline gnawing at him, Hepton felt a sudden inner calm. All would be well. It was just a matter of trusting to fate and pushing the right buttons. Who was he kidding? Zephyr was lost for good.

Someone was standing behind him. He glanced back and saw Paul Vincent watching intently over his shoulder. Vincent was the youngest of the controllers, and the least confident.

‘Come to see how the professional does it, Paul?’ Hepton said, grinning nervously at the screen. He saw Vincent’s reflection smile wanly back. Then he began pushing buttons again, trying every combination possible. He had used up all the rational choices. Now he was trying the irrational, asking the computer to do the impossible.

Paul Vincent’s face was suddenly at his ear, though the young man’s eyes still appeared to be studying the monitor.

‘Listen, Martin, there’s something I want to show you.’

‘What?’

Vincent’s gaze remained fixed to the screen. His voice was low, just audible over the noise all around.

‘I can’t be sure,’ he said, ‘not a hundred per cent, at any rate. But I think there’s something happening up there. Either that or I’ve been doing something wrong. I had it on my screen a little while back.’

‘What do you mean, “something happening”?’

‘I’m not sure yet. Foreign data.’

‘Have you reported it?’

‘Of course.’

Perhaps that was why the brass were on the scene, and why they had looked momentarily scared.

‘Are we talking about interference?’ Hepton’s voice was low too.

‘I don’t know. I could make a wild guess, but I’m not sure it would help. I’d like you to confirm the data.’

‘When did it start?’

‘About half an hour ago.’

‘Coincidence?’

There was a sudden whoop, then cheers and some applause.

‘We’ve got her back!’

Hepton’s eyes went to his screen. They had indeed got her back. He was staring at a fuzzy but identifiable picture of Britain, taken from all that unbelievable distance. The image was out of focus, but they could soon put that right. What mattered was that Zephyr was working again.

‘Panic over,’ he said, turning now to face Paul Vincent. ‘So what about this foreign data?’

‘I’ve saved the readout on disk. Come and see.’