“The Marchioness might not like it,” I said, driven back to the second line of fortification. “You know your mistress is very particular about these emeralds.”

“The Marchioness need never know,” Susan Berry whispered, putting her face close up to mine. “No one need know, except just us two.”

The accent which she put on those three words “just us two,” was extremely tender.

I hesitated. We were already at the end of the Square, and should have turned down to the left towards Cockfosters House.

“Come along,” she entreated, placing her hand on my shoulder.

“Well, you know——” I muttered, but I went along with her towards Sloane Street. We passed Eaton Place.

“Really, Miss Berry——” I began again, collecting my courage.

Then there was a step behind us, and another hand was placed on my shoulder. I turned round sharply. It was a policeman. His buttons shone in the moonlight.

“Your name is Charles Saunders,” he said to me; “and yours Susan Berry,” to my companion.

“True,” I replied, for both of us.