‘We’ll decide whether we think you were spying once we get you back to the guardhouse.’

‘Spying? Why on earth would I . . .?’

‘That’s exactly what you’re going to tell us. And at that point it may be a matter for the police.’

The police? This was serious. Pa and Ma knew most of the coppers based in the town, and would be bound to find out. ‘Look, please, just let me go and I’ll head over to the marshes, which is where I’d originally intended to go.’

‘Just be quiet and walk, miss. You’ll have your say once I’ve got the boss down here.’

At the guardhouse she was taken to a dismal, dimly lit room with metal bars at the window, furnished only with a small table and four hard chairs. As he left, the key turned in the door from the outside. She was actually locked in. In the silence, she could hear her heart pounding in her chest. How could they possibly think she was a spy?

After what seemed like an hour, the guard returned with another man, tall and moustachioed, wearing a suit and tie. ‘Well now, what have we here?’ His smooth demeanour and unsettlingly quiet, assured voice was somehow even more terrifying than the threats of the burly man with the gun. ‘Now I want you to take a seat and listen to me, miss. Tell me your name, age and address, the names of your parents, if any, what school you go to and where you were born.’ As she tried to gather her thoughts and answer calmly, the guard painstakingly recorded everything in a yellow lined notebook, his chubby fingers struggling to manipulate a blunt stub of pencil.

‘Honestly, I promise. Hand on heart. I was birdwatching. There’s a book in my backpack. Ask Charlie Brinkley.’

The man sighed. ‘I’m afraid Jenkins here doesn’t believe the birdwatching story on account of the fact that you were clearly looking through your binoculars to observe our mast, which led him to conclude that you were probably spying. You can hardly be unaware that this is a top secret facility, miss?’

She nodded.

‘So perhaps you would like to explain precisely what it was you were looking at, and why.’

‘I wasn’t spying. All I wanted was to find out a bit more . . .’

‘What is the difference between “finding out more” and spying, would you say, miss?’

‘Look, I know it was stupid, but I wasn’t doing it for anyone else, I promise. It was just to satisfy my own curiosity. I’m so sorry. It won’t happen again.’

For a few long moments he said nothing. Then, at last, he sat back in his chair. ‘Well, Miss Motts, I am inclined to conclude that you are just a silly young girl who is completely unaware of the seriousness of her actions. But I’m afraid we will have to record the details of this incident in our security log and we will also, as a matter of course, pass them to the local constabulary.’