Annie Haynes (1865-1929) was the daughter of an ironmonger. By the first decade of the twentieth century she lived in London and moved in literary and early feminist circles. Her first crime novel, The Bungalow Mystery, appeared in 1923, and another nine mysteries were published before her untimely death. Who Killed Charmian Karslake? appeared posthumously, and a further partially-finished work, The Crystal Beads Murder, was completed with the assistance of an unknown fellow writer, and published in 1930.