NICK CARTER STORIES _Issued Weekly. Entered as Second-class Matter at the New York Post Office, by_ STREET & SMITH, _79-89 Seventh Ave., New York. Copyright, 1915, by_ STREET & SMITH. _O. G. Smith and G. C. Smith, Proprietors._ Terms to NICK CARTER STORIES Mail Subscribers. (_Postage Free._) Single Copies or Back Numbers, 5c. Each. 3 months 65c. 4 months 85c. 6 months $1.25 One year 2.50 2 copies one year 4.00 1 copy two years 4.00 =How to Send Money=--By post-office or express money order, registered letter, bank check or draft, at our risk. At your own risk if sent by currency, coin, or postage stamps in ordinary letter. =Receipts=--Receipt of your remittance is acknowledged by proper change of number on your label. If not correct you have not been properly credited, and should let us know at once. =No. 145.= NEW YORK, June 19, 1915. =Price Five Cents.= AN UNSOLVED MYSTERY; Or, NICK CARTER’S GOVERNMENT CASE. Edited by CHICKERING CARTER. CHAPTER I. A SECRET CONFERENCE. The old gentleman passed the other two as if they were strangers. He jostled by them without so much as a glance. The most observing person in the throng then pouring out of the railway station, like a swarm of busy bees out of a colossal hive, would have detected no relation between them. While passing the couple, nevertheless, the old gentleman said quickly to one of them, though scarce above his breath: “Go to the new Willard. Register as directed, and get a suite, Wait there till I come.” The man addressed heard him, but did not turn his head, nor evince the fact with the slightest change of countenance. His companion, a natty, keen-eyed chap with a blond mustache twirled upward at the ends à la kaiser, appeared oblivious to what had occurred. The scene of this trivial episode, which was far more portentous than one would suppose, having a bearing on no less tremendous an issue than the possible fate of a nation, was the new Union Station in the city of Washington, and the hour was two o’clock one fine afternoon in October. The old gentleman hastened out with the throng into Massachusetts Avenue, seeking a trolley car and mingling with the crowd in a plebian sort of a way, as if business of no great importance had brought him to the nation’s capital.