‘Where would you like to go? To the sea?’ Mark asked as they set off.

‘No, it breaks my heart to see all those barricades on the beach,’ Kath said. ‘Let’s walk in the marshes. At least there we can half pretend there’s not a war on.’

Here, in the open spaces of salty wetland, they were able to speak more freely. He asked about her time at HQ, and about her new posting.

‘What about you?’ she asked.

He shrugged. ‘Flying a bomber is like driving an elephant after those lovely little Spitfires, but you’ve got five or six others on board with you so there’s a great team spirit. We keep each other going.’

‘Do you ever worry about the people down below?’

‘The ack-acks trying to kill us?’

‘The civilians, I mean. Like the people who copped it from the Germans in London and Coventry.’

‘Of course, but you try not to think about it too much. We don’t have any choice, to be honest. We won’t defeat the Germans unless we can destroy their industries, so that’s got to be our priority. We try to avoid residential areas.’

A flock of ducks rose into the sky with a noisy chorus of alarm calls.

‘There goes a good supper,’ Mark said.

‘We sometimes mistake them for aircraft,’ she said.

‘Friend or foe?’

‘It soon becomes apparent when they start wheeling about.’

‘You’re right. We don’t do a lot of wheeling these days.’

They laughed and walked on. Low sunlight streaked rays of gold across the marshes.

‘It’s so beautiful here,’ she said. ‘It’s easy to forget, sometimes, what we’re fighting for.’

He gave a small sigh and stopped walking. She turned. ‘What is it, Mark?’

‘I just wanted to say . . .’ He took another breath. ‘Has anyone ever told you how reassuring it is to know that you lot are tracking us, Kath? A few weeks ago some of our guys had to ditch into the sea and the rescue team was there in minutes. Said they’d been alerted by you lot.’

‘What day was that?’ He told her. ‘Blimey, that was on my first ever shift! I saw them, Mark. I was so worried. Thank heavens they were okay.’

‘You saved a few good men that night.’

‘That’s amazing. Makes it all worthwhile, knowing that.’

‘They were heading for Sutton Heath. Just didn’t quite make it.’

‘Sutton Heath?’

He paused. ‘Perhaps I’ve said too much. It’s top secret, so you won’t say anything, will you?’

‘Of course not. Tell me.’

‘Sutton Heath. Official name RAF Woodbridge. It’s an emergency landing strip, what they call a crash ’drome, a ruddy great long runway – three of them, actually – with all the rescue equipment, fire engines, medical facilities and the rest, for any plane in distress, low on fuel, whatever. They’re on standby twenty-four hours a day, seven days a week. They even burn fires to disperse fog on bad nights. Stanmore alerts them, based on your reports.’