“Again I acquiesced.  I admit, I was curious.

“‘We assume,’ said she, ’that between France and Germany you are indifferent.’

“‘Paris and Berlin have each their good points,’ I replied.

“‘Quite so,’ she acquiesced; ’just now, however, we ask you to favour Berlin and for a consideration.’

“‘I don’t want a consideration,’ I smiled; ’tell me what’s the favour you seek?’

“‘We ask you,’ she replied instantly, ’to take a letter to the French Ambassador and tell him that it is the letter Madame Durrand gave you in New York, and that it has just been returned to you by the American State Department.’

“‘Have you the letter with you?’ I asked.

“‘I have,’ she replied, producing it from her bag.  ’It may not exactly resemble the original.’

“‘It doesn’t,’ said I.

“‘But the French Ambassador won’t know it,’ she smiled.  ’Further, so as to make the matter entirely regular with you, you will receive an appointment in the German Secret Service and five thousand dollars in advance.’

“‘Is it usual to—­change sides so suddenly?’ I asked.

“‘You’re not changing sides,’ she explained.  ’You’ve never had a side, in the diplomatic sense.  It is entirely regular in diplomacy for you to take such a course as is proposed; there is nothing unusual about it.  And, my dear Mrs. Clephane, a position in the German Foreign Secret Service is a rare plum, I can assure you, even though you may not care to be—­active in it.’

“Naturally, I understood.  Mrs. Spencer thinking me the same type as herself, without conscience, character, or morals, had evolved this plan either to test me or to ensnare me.  To test me, because she is jealous of you; or to ensnare me because she wants to win out diplomatically—­or both, it may be.  I am a poor hand at pretence; but I played the game, as you would say, to the best of my ability.  So I seemed to fall in with her scheme; France was nothing to me; I had been given no option in the matter of accepting the letter and attempting its delivery; I had done all and more than could be expected of a disinterested person; I had lost the letter but through no fault of mine.  I was acquitted of further responsibility; was at liberty to choose.  And Mrs. Buissard agreed with me in everything.  In the end, I accepted the spurious letter for delivery to the French Ambassador.”

“Good!” Harleston applauded.  “You’re learning the method of diplomacy very rapidly; fire with fire, ruse with ruse, deceit with deceit—­anything for the object in hand.”

“It went against me to do it,” she admitted, “but I’ll pay them in their own coin—­or something to that effect.  Of course, I’ve no intention of delivering the letter to the French Embassy.  I’ll deliver it to you instead.”

“Delightful!” Harleston exclaimed.  “You’re a bully diplomat.  However, I’m not so sure that Spencer ever imagined her letter would reach the Marquis.  She’s playing for something else, though what is by no means clear.  Let us have a look at the letter; maybe it will help.”