As well as considering why Australian writers should choose to write science fiction and the relationship between science fiction and fantasy, the introduction also briefly discusses plots and themes of most of the short stories in this anthology.

This story was first published in the Australasian, 14 September, 1872, with the title 'Human Repetends'. This version of the story, which includes a character called Marston, has been republished several times in anthologies and selections. A second version of the story, with a different beginning and featuring a character called Hylton, was first published in the posthumous selection Sensational Tales with the title 'A Mysterious Coincidence'. This version has been republished under both titles.