“On the contrary,” said the Baron, “I am at a loss for suitable words in which to express my singular request.  I am assured of your interest, Poynter?”

“Of my interest, assuredly!” admitted Philip.  “My compliance,” he added fairly, “depends, of course, upon the nature of the mission.”

“It is absurdly simple,” said the Houdanian suavely.  “Merely to discover whether or not the nomadic lady feels any exceptional interest—­in Houdania.  For the information to be acquired in a careless, disinterested manner without arousing undue interest, requires, I think, an American of brains and breeding, a compatriot of the nomad.  It has occurred to me that you are equipped by a habit of courtesy and tact to—­arrive accidentally in the path of the caravan—­”

“I thank you!” said Philip dryly.  “I prefer,” he added stiffly, “to confine my diplomatic activities to more conventional channels.”

“When I assure you,” purred the Baron with his maddening precision of speech, “that this information is of peculiar value to me and without immediate significance to the lady herself, I am sure that you will not feel bound to withhold your—­hum—­your cooeperation in so slight a personal inconvenience, singular as it may all seem to you, I am right?”

Philip reddened uncomfortably.

“I am to understand that I would undertake this peculiar mission equipped with no further information than you have offered?”

“Exactly so,” said the Baron.  “I must beg of you to undertake it without question.”

“Pray believe,” flashed Philip, “that I am not inclined to question.  That fact,” he added coldly, “is in itself a handicap.”

“The lady’s name,” explained the Baron quietly, “is Westfall—­Diane Westfall.”

“Impossible!” exclaimed Philip and savagely bit his lip.

“Ah, then you know the lady!” said the Baron softly.

“I regret,” said Philip formally, “that I have not had the honor of meeting Miss Westfall.”  But he saw vividly again a girl straight and slender as a silver birch, with firm, wind-bright skin and dark, mocking eyes.  There were hemlocks and a dog—­and Dick Sherrill had been talkative over billiards the night before.

“Miss Westfall,” added Philip guilelessly, “is the owner of the Glade Farm below here in the valley.”

“Ah, yes,” nodded Tregar.  “It is so I have heard.”  His glance lingered still upon Philip’s face in subtle inquiry.  Bending its Circean head, Temptation laughed lightly in Philip Poynter’s eyes.  The girl in the caravan was winding away by dusty roads—­out of his life perhaps.  And singular as the mission was, its aim was harmless.

“Our lady,” said the Baron smoothly, “camps by night.  From an aeroplane one may see much—­a camp—­a curl of smoke—­a caravan.  Later one may walk and, walking, one may lose his way—­to find it again with perfect ease by means of a forest camp fire.”