The Moon Is a Harsh Mistress
Gwen Novak is eventually revealed to be Hazel Stone, a character previously featured in Heinlein's "The Rolling Stones" and who had played a small but important role in "The Moon Is a Harsh Mistress". Campbell is also eventually revealed to be a son of Lazarus Long, a Heinlein character originally introduced in "Methuselah's Children" and who reappeared in "Time Enough for Love", "The Number of the Beast", and "To Sail Beyond the Sunset". Also appearing are Jubal Harshaw, a major character in "Stranger in a Strange Land"; Galahad, of "Time Enough for Love"; and Manuel Garcia O'Kelly Davis, the first-person voice of "The Moon Is a Harsh Mistress".