CHAPTER XVIII--GRACE GETS A CLUE 193 “You are the quickest-witted person I ever knew.” “Captain” Grace “savvies” Yat Sen. The voice from the cellar. The doctor has a visitor. A house of mystery. “I am right or else I am terribly wrong,” mutters Grace Harlowe. CHAPTER XIX--A VOICE AND A FACE 200 “I must see who comes out of that house.” Grace shatters the doctor’s argument. “The Germans are unsportsmanlike losers.” Checkmated! Rebuked by the supervisor. Grace meets a suspected person and smiles a gentle greeting. CHAPTER XX--IN A MAZE OF MYSTERIES 211 Won “savvies” too much talk. Playing the game both ways. Molly leads the supervisor from the canteen. Complaint is lodged against “Captain” Grace. Suspicions confirmed. The Overton girl makes a discovery. Grace gives a warning and borrows an auger. CHAPTER XXI--A MOUSE IN THE TRAP 224 Grace bores a hole through the floor of her room. The German maid refuses a tip. When conversation ran wild. “Planning to shoot up our friends across the Rhine.” Grace Harlowe is amazed at what she overhears. CHAPTER XXII--“CAPTAIN” GRACE DECIDES TO ACT 233 Elfreda is taken into the secret. “I never dreamed of anything so terrible as this.” Grace suspects that she is being watched. The intelligence officer gets an unusual invitation. The mine is laid. CHAPTER XXIII--A DESPERATE PLOT REVEALED 242 Captain Boucher makes his call through a window. “Should any one knock, crawl under the bed.” The intelligence officer forgets his boots. A strange scene in the Overton girls’ quarters. CHAPTER XXIV--THE TRAP IS SPRUNG 246 A signal that was instantly obeyed. Ordered to headquarters. Army officers get a genuine surprise. Grace Harlowe reveals a deep-laid Hun plot. The fight and the capture in the Overton girls’ billets. Heroes who work in the shadows. GRACE HARLOWE WITH THE AMERICAN ARMY ON THE RHINE CHAPTER I ON THE MARCH TO THE RHINE “Here is where we take on our load,” observed Grace Harlowe, backing her car up to the door of a peasant cottage. “Never was a truer word spoken,” agreed J. Elfreda Briggs. “Chad of her own sweet self is considerable of a load.” Miss Briggs reached back and threw open the door of the army automobile, to be ready for their passenger who had not yet appeared. “Baggage, some would characterize her,” added the girl. “She is our superior, Elfreda,” reminded Grace. “One always must preserve a certain respect for one’s superior, else discipline in the army will quickly go to pieces. While Mrs. Smythe plainly is not all that we wish she were, she is our superior officer whom we must both respect and obey.” “Ever meet her?” questioned Elfreda.