“Are you quite certain that this Mr Drury is unaware who you really are?” I asked.

“Quite. He believes me to be Miss Natalia Gottorp, my father German, my mother English, and I was born in Germany. That is the story—does it suit?”

“I trust you will take great care not to reveal your true identity,” I said.

“I have promised you, haven’t I?”

“You promised me that you would not flirt, and yet here you are, having clandestine meetings with this young man every evening!”

“Oh, that’s very different. I can’t help it if I meet an old friend accidentally, can I?” she protested with a pretty pout.

At that moment we were strolling along the western side of the pierhead, where it was comparatively ill-lit, on one side being the theatre, while on the other the sea. The photographer’s and other shops were closed at that late hour, and the light being dim at that spot, several flirting couples were passing up and down arm in arm.

Suddenly, as we turned the corner behind the theatre, we came face to face with a dark-featured, middle-aged man, with deeply-furrowed brow, narrowly set eyes and small black moustache. He wore a dark suit and a hard felt hat, and had something of the appearance of a middle-class paterfamilias out for his annual vacation.

He glanced quickly in our direction, and, I thought, started, as though recognising one or other of us.

Then next moment he was lost in the darkness.