I Up the Ladder
II The Radio from the Sky
III A Message in Code
IV Danny Duke Makes a Catch
V Danny Shares a Secret
VI Through a Hole in the Sky
VII Silent Storm
VIII Danger is My Duty
IX Sally Steps Out
X Sally Saves a Life
XI Secret Meeting
XII They Fly at Dawn
XIII Among the Missing
XIV The Captain’s Dinner
XV Danny’s Busy Day
XVI The Dark Siren
XVII Little Shepherdess of the Big Ships
XVIII The Secret Radio Wins Again
XIX Oh, Danny Boy!
XX A Gleam from the Sea
XXI Dreams
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