Mary Roberts Rinehart’s first two novels “The Circular Staircase” and “The Man in Lower Ten” inaugurate The Essential Rinehart Collection, a new book series destined to entertain readers for many years.   “The Circular Staircase” tells the story of how Miss Cornelia Van Gorder lost her mind, deserted her domestic gods in the city, took a furnished house for the summer out of town, and found herself involved in one of those mysterious crimes that keep newspapers and detectives happy and prosperous. “The Man in Lower Ten” is a legal thriller featuring a detective who builds up a network of clues that absolutely incriminate three entirely different people, only one of whom can be guilty.  These novels, which combine mystery and adventure, demonstrate Rinehart's tremendously vivid powers as a storyteller.  Well-written and fast-paced, these mysteries will leave you eager to read the other volumes in this series.