THE SINISTER MARK BY LEE THAYER GARDEN CITY NEW YORK DOUBLEDAY, PAGE & COMPANY 1923 COPYRIGHT, 1923, BY DOUBLEDAY, PAGE & COMPANY ALL RIGHTS RESERVED, INCLUDING THAT OF TRANSLATION INTO FOREIGN LANGUAGES, INCLUDING THE SCANDINAVIAN COPYRIGHT, 1923, BY THE FRANK A. MUNSEY COMPANY PRINTED IN THE UNITED STATES AT THE COUNTRY LIFE PRESS, GARDEN CITY, N. Y. _First Edition_ TO H. W. T. IN GRATEFUL ACKNOWLEDGMENT OF HIS FINAL APPROVAL CONTENTS I. "MARY BLAKE" II. AN UNSTAMPED LETTER III. PETER CLANCY IV. A VIEWLESS ROOM V. CAMOUFLAGE? VI. "MY SISTER, ANNE----" VII. A SPLASH OF BLOOD VIII. THE VOICE OVER THE WIRE IX. WHAT THE CABMAN KNEW X. A BIG TRUNK XI. FOUR PHOTOGRAPHS XII. A SIGNATURE CARD XIII. THE WOMAN AT THE PENNSYLVANIA HOTEL XIV. ONE CLUE XV. THE DUPLICATE KEY XVI. ROSAMOND CURWOOD XVII. ANOTHER PHOTOGRAPH XVIII. ROSAMOND'S SECRET XIX. IN THE OLD PHOTOGRAPH GALLERY XX. PETER CLANCY CHANGES HIS PLANS-- XXI. --AND ASKS A QUESTION XXII. "ON MONDAY--THE TWENTY-NINTH OF MAY----" XXIII. A MIDNIGHT ERRAND XXIV. "HANDS UP!" XXV. A HIGH WALL XXVI. THE WOMAN SHULTZE XXVII. 111 WEST FORTY ---- STREET XXVIII. DONALD MORRIS UNDERSTANDS XXIX. KATE RUTHERFORD RELIEVES HER MIND THE SINISTER MARK CHAPTER I "MARY BLAKE" "Tell me, Mary!"