Work was busier than ever. Now, dotted all around the south and east coasts of England, more than twenty stations operated a twenty-four-hour, seven-day-a-week watch, with their results communicated to a central base at Stanmore. Planes could now be tracked from a hundred and fifty miles, and new wavelengths were being trialled so that even the low-flying craft that had previously proved so elusive could now be detected. Flocks of birds sometimes triggered alarm, but the operators became skilled at recognising the difference between true and false echoes.

Vic’s special pride and joy, the IFF Mark II, was already installed in hundreds of planes, allowing them to be distinguished from enemy craft. An improved version, the Mark III, was being tested. There was much more to be done, of course, and Dr Rowe was still driving the boffins to come up with better solutions, but at least they had the satisfaction of knowing that Britain’s air defences were no longer dependent on primitive concrete ‘dishes’ angled at the sky in vain hopes of picking up the sound of an aircraft before you saw it.

At Bawdsey, the transmitter block was in operation and four soaring masts, each nearly half the height of the Eiffel Tower, were in the final stages of testing. The IFF Mark III transmitters had been installed at the top of one of the masts, but still needed fine calibration. The engineers had been up the mast several times, but still the glitches continued.

Dr Rowe was becoming impatient. ‘What seems to be the problem?’ he asked, at the team meeting.

‘The calibration of the transmitting kit, sir,’ Frank volunteered. ‘On the mast.’

‘Then get someone to fix it,’ was the terse reply.

‘The engineers . . .’

‘I don’t want excuses, Wilkinson,’ Dr Rowe interrupted. ‘I’ve seen them up there every day, and whatever they’re doing isn’t working. One of you lot will have to go and have a look. Report back to me once you’ve done it.’

‘Bloody hell,’ someone muttered, after he’d gone.

The team shared shocked glances. ‘So who’s it going to be, then?’ another asked.

‘Frank? It’s your baby.’ He was the obvious choice, with his particular sphere of expertise.

‘Sorry, folks,’ he said, quickly. ‘But that stew they served last night has given me a dicky tummy. You wouldn’t want to be anywhere below me for the next twenty-four hours,’ he added, to much laughter.

Vic’s own stomach clenched into painful knots. ‘I’m really not good at heights,’ he muttered, looking at Scott.

‘Me neither,’ Scott said.

There was a momentary impasse, until someone suggested: ‘Why don’t we toss for it?’

For the first time in weeks he heard Johnnie’s voice. Go for it, Vic. Prove yourself to Frank and the rest, once and for all.

Get lost, old mate, he replied in his head. Unless you want me joining you sooner than I’d planned. Then he took a deep breath and said out loud, ‘No, don’t bother tossing a coin. I’ll do it.’