The Secret Service SubmarinePart 3 — CHAPTER XIIReading editionChapter navigation18 reading sectionsGo to chapterChoose a chapter…THE SECRET SERVICE SUBMARINEPART IPART IIPART IIIChapter IChapter IIChapter IIIChapter IVChapter VChapter VIChapter VIIChapter VIIIChapter IXChapter XChapter XIChapter XIIPart I.—Doris and Marjorie have a Late VisitorPart II.—Return of the Seven HeroesPrevious chapter ←Part 3 — Chapter XINext chapter →Part 1 — Part I.—Doris and Marjorie have a Late VisitorAll chapters and sections (18)Other sectionsTHE SECRET SERVICE SUBMARINEParts123Part 1 · Chapters1234Part 2 · Chapters5678Part 3 · Chapters9101112Part 1 · Parts1Part 2 · Parts2THE LAST CHAPTER—IN TWO PARTS← CHAPTER XIPart I.—Doris and Marjorie have a Late Visitor →