CONTENTS

CHAPTER
I. [THE BLACK IMP]
II. [A MYSTERIOUS PACKAGE]
III. [THE THREAT]
IV. [FOLLOWING AMY'S TRAIL]
V. [BEHIND THE PANEL]
VI. [A HOLDUP]
VII. [AN INVITATION TO LUNCH]
VIII. [A BOLD MOVE]
IX. [THE ROBBERY]
X. [HANLEY CRON'S STUDIO]
XI. [A VISITOR]
XII. [THE MISSING WORKMAN]
XIII. [AN EMBARRASSING INTERVIEW]
XIV. [THE MYSTERIOUS AGENT]
XV. [A PUZZLING LETTER]
XVI. [WATCHFUL WAITING]
XVII. ["PRIVATE—KEEP OUT"]
XVIII. [CAPTURED]
XIX. [FIRE!]
XX. [THE SECRET REVEALED]