Fitz-James O'Brien was born in Cork, Ireland in 1826. After studying at the University of Dublin where he showed a talent for writing poetry, he moved to London. In 1852 he emigrated to America and settled in New York where he earned his living by journalism and publishing stories in leading magazines, becoming an influential figure in the city's bohemian set. In 1861 at the outbreak of the Civil War he enlisted in the New York National Guard. The following year he was wounded and died from tetanus. He was 35. He is considered an important early writer of science fiction. His three probably best known stories are included in this volume. They are:

"The Diamond Lens"
"What Was It?"
"The Lost Room"