Flora Cranley was the daughter of Dr. Cranley and fiancee to her father's assistant, Dr. Jack Griffin. Little is known of Flora, except that she loved Jack very dearly in spite of his secretive and often reclusive nature. She was also the object of affection for her father's other assistant, Dr. Arthur Kemp, although Flora had no love for Arthur (much to Arthur's bitter resentment of Jack).
When Arthur phoned the Cranley residence to inform his boss that Jack Griffin, who had gone missing some months before, was not only in his house but was also the murderous invisible man that was reputed to be on the loose, Flora overheard her father's end of the conversation and demanded to accompany him to Arthur's house so that she could see Jack. Although Dr. Cranley initially refused, his daughter's resolve persuaded him to let her come along.
Once at Arthur's, Flora met with Jack, who was wearing bandages and dark goggles so that he could be visible to her. Their tender reunion was short-lived, as several police officers under the direction of Inspector Lane, summoned by a panicky Arthur, arrived and Jack was forced to flee. The next time Flora would see Jack, tragically, was when he was on his deathbed in the hospital.