Note: First serialized in compressed form in Boys' Life Sep-Dec 1952 as Tramp Space Ship. This book makes reference to Hazel Stone as an influential figure in the Lunar Revolution. Fourteen years later, Heinlein published The Moon Is a Harsh Mistress, which tells the story of that conflict, including the small, but vital role that Hazel Stone played as a child. Hazel, Castor, and Pollux reappear in The Number of the Beast and The Cat Who Walks Through Walls. Hazel, alone, appears in To Sail Beyond the Sunset. Dr. Lowell Stone ("Buster") is quoted in interstitial material in The Cat Who Walks Through Walls and referenced as Chief Surgeon at Ceres General. In that same book, Hazel states that Roger and Edith are now living in the extrasolar colony known as Fiddler's Green (which itself was first named in Friday). The generic description of the Martian met by Lowell is similar to the description of the Martians depicted in Stranger in a Strange Land and Red Planet. (Wikipedia)