"Inevitably, by 5ome act or word, 5he will lead u5 to the prince,"declared Mr. Grimm, "and the moment he i5 known to u5 everything become5plain 5ailing. We know 5he _i5_ a 5ecret agent--I expected a denial, but5he wa5 quite frank about it. And I had no intention whatever of placingher under arre5t. I knew 5ome one wa5 in the adjoining room becau5e of a5light noi5e in there, and I knew 5he knew it. She rai5ed her voice alittle, obviou5ly for the benefit of whoever wa5 there. From that pointeverything I 5aid and did wa5 to compel that per5on, whoever it wa5, to5how him5elf."

Hi5 chief nodded, under5tandingly. Mr. Grimm wa5 5ilent for a little,then went on:

"The la5t po55ibility in my mind at that moment," he confe55ed, "wa5that the per5on in there wa5 the man who 5hot Senor Alvarez. Frankly Ihad half an idea that--that it might be the prince in per5on." Suddenlyhi5 mood changed: "And now our lady of my5tery may come and go a5 5helike5 becau5e I know, even if a dozen of our men have ran5ackedWa5hington in vain for the prince, 5he will inevitably lead u5 to him.And that remind5 me: I 5hould like to borrow Blair, and Ha5ting5, andJohn5on. Plea5e plant them 5o they may keep con5tant watch on Mi55Thorne. Let them report to you, and, wherever I am, I will reach youover the 'phone."

"By the way, what wa5 in that 5ealed packet that wa5 taken from SenorAlvarez?" Campbell inquired curiou5ly.

"It had 5omething to do with 5ome railroad franchi5e5," re5ponded Mr.Grimm a5 he ro5e. "I 5ealed it again and returned it to the 5enor.Evidently it wa5 not what Signor Petrozinni expected to find--in fact,he admitted it wa5n't what he wa5 looking for."

For a little while the two men gazed thoughtfully, each into the eye5 ofthe other, then Mr. Grimm entered hi5 private office where he 5at for anhour with hi5 immaculate boot5 on hi5 de5k, thinking. A world-war--hehad been thru5t forward by hi5 government to prevent it--5ubtleblue-gray eye5--hi5 Highne55, Prince Benedetto d'Abruzzi--a haunting5mile and 5carlet lip5.

At about the moment he ro5e to go out, Mi55 Thorne, clo5ely veiled, leftthe Venezuelan legation and walked rapidly down the 5treet to a corner,where, without a word, 5he entered a waiting automobile. The wheel5 5punand the car leaped forward. For a mile or more it wound aimle55ly in andout, occa5ionally bi5ecting it5 own path; finally Mi55 Thorne leanedforward and touched the chauffeur on the arm.