Mary E. Penn is an enigmatic figure – nothing whatsoever is known about her other than the fact that she wrote several stories for late-Victorian periodicals, most notably The Argosy, a monthly miscellany associated with the sensation novelist Ellen Wood (not to be confused with the American periodical of the same name). Penn’s fiction encompassed supernatural and criminal themes and the last story definitely attributed to her appeared in 1897. More details about Penn and her stories can be found here.
In 1999, Richard Dalby resurrected Penn’s ghost stories for inclusion in his Mistresses of the Macabre series, published by Sarob Press. In the Dark and Other Ghost Stories (the second in the series) featured seven stories definitely attributed to Penn, and one which was published anonymously, but which Dalby ascribes to Penn on stylistic grounds. For this edition I’ve used the texts as published in The Argosy, most issues of which are available online. A linked index to each volume can be found here and is well worth having a browse for more hidden gems of Victorian genre fiction.