Introductory material
Reading edition
CHAPTERS I. Why the Danger Sign Was Up II. Torpedo Practice at Last III. Struck by a Submerged Foe IV. A Submariner's Revenge V. The Mysterious Order Comes VI. Judas & Co. Introduce Themselves VII. Eph Sommers Plays Gallant VIII. One, Two, Three—A Full Bag IX. But Something Happened Next X. John C. Rhinds Advocates Fair Sport! XI. The Strain of Red-Hot Metal XII. Let a Sailor Stick to Her Deck XIII. The Trick is Easily Seen Through XIV. Radwin Doesn't See His Best Chance XV. The Goal of the Lightning Cruise XVI. Jack Gives the Order. "Fire!" XVII. The Message of Terror XVIII. The Findings on the "Thor" XIX. On the Other Side of the Forced Door XX. Captain Jack Pulls a New String XXI. Jack Meets a Human Fact, Face to Face XXII. A Cornered Submarine Captain XXIII. A Coward's Last Ditch XXIV. Conclusion