B. M. Croker (1848-1920) was an Irish-born novelist and a notable writer of ghost stories.

'Number Ninety' is one of Croker's best-known ghost tales and was first published in the Christmas Number of Chapman's Magazine of Fiction in 1895.

At a rowdy dinner party, the discussion turns to ghosts, and John Hollyoak, the most outspoken and derisive of the nonbelievers, declares that he would like to spend the night in a haunted house. So, the host of the party arranges for him to do just that.