‘What the hell’s he playing at? Ruddy thing’s wheeling round like a Catherine wheel,’ the WAAF swore.

Wheeling. The words she’d said to Mark: It soon becomes apparent when they start wheeling about. ‘Is it hostile?’ she called. ‘Strange time for reconnaissance.’

‘Can’t tell. The IFF signal seems to be playing up again. Sometimes I see it, then I don’t.’

Monty groaned. ‘I thought we’d fixed it? It was working okay before.’

The WAAF fiddled with the controls. ‘Nope, can’t see it. Not at all.’

Kath ran back to look over her shoulder. It was definitely a single blip. For a few seconds, she thought she saw the second spike on the screen that would indicate friendly craft, but it disappeared so fast she fancied she must have imagined it. There it was again. Now it had gone.

‘D’you mind if I have a go?’

‘Be my guest,’ the WAAF said, relinquishing her seat.

Kath sat at the controls, her right hand on the goniometer wheel. Nudging it gently clockwise, then anti-clockwise, she took readings: height, range and trajectory. She peered at the screen so hard that her eyes burned. Definitely no double blip. She stood up again and the WAAF resumed her place.

‘Nope, nothing.’

‘Best inform Stanmore, anyway,’ someone said.

Kath’s head whirled. ‘And have them send a fighter to shoot the poor bastard down?’ she said. It would be her responsibility to make the call, but what if the plane was ours? What if it was Mark?

‘That “poor bastard” might be coming to bomb us.’

‘But are we really sure it’s hostile?’

‘We have to leave it to them to decide. They’ll have tracks from other stations, after all. Make the call, Kath,’ someone said.

She hesitated.

‘Do it, Kath.’ More urgently this time. ‘Before they bloody well blow us to kingdom come.’

As the phone operator on rota, it was her duty. She dialled and spoke into the receiver, giving the identification code for the station, followed by the time. ‘Craft acting suspiciously, possibly hostile,’ she said, giving range, height and co-ordinates.

‘Roger that, thank you.’ As she replaced the receiver it felt as heavy as a stone.

Everyone was still gathered around the screen, watching as the plane continued to circle, up and down the coast. It was like nothing they’d observed before and hardly likely to be activity of an enemy aircraft, they all agreed. Kath became more and more convinced that the plane and its crew were in trouble, trying to find their route to the crash ’drome at Sutton Heath.

Ten minutes later they tracked a fighter, heading out towards their latest sighting.

‘If they’re German, they’re toast,’ someone said, and the others cheered.

But what if they’re not? The question repeated itself over and over in Kath’s head. But what if they’re not?

Moments later, just as the other girls arrived to take over the shift, all trace of the mysterious plane disappeared. Even though she felt nauseous with anxiety and fatigue, she waited as they tracked the fighter home, and the screens cleared of all signals.