Helen, Margy and Rose Blythe return in this sixth novel devoted to their adventures. Picking up directly where the previous installment, Three on a Vacation, or, The Mystery at Peach Farm, left off, the story opens as the sisters and their friend Laura Small head back to the city from their holiday at Peach Farm. On the train ride in, they meet Mrs. Sally Whitson, a widow journeying to the home of her niece, where she is unsure of her welcome. Losing sight of this new acquaintance, the girls are met by their various beaus and boy friends at the train station, and are soon absorbed in their New York lives again. Helen becomes closer to fellow artist Dick Banning, to the chagrin of her long-time friend, Hugh, while Rose and Laura return to their jobs at the department store. Margy, in the meantime, must contend with Dale and Lloyd, who vie for her attention, and returns to her own job as assistant to the wealthy Mrs. Pepper. Here she discovers that her employer's extremely dubious nephew, Rex Pepper, is once again up to no good. Mrs. Pepper dispatches her to Shadymere, the Long Island home of likely embezzler and crook, Mr. Clever-Carlton, to investigate his connection to Rex, leading to the unraveling of a mystery, and the restoration of stolen and/or lost property to Mrs. Pepper, Mrs. Whitson, and Mr. Bullard, the art dealer who buys most of Helen's work...

With the notable exception of Three on a Vacation, or, The Mystery at Peach Farm, which I found distasteful because of its xenophobic depiction of Italian-Americans, I generally enjoy The Blythe Girls books, which follow the adventures of three sisters as they make their way through life in 1920s New York City. It's fascinating to see the city where I have lived and worked in a different era, and to note the differences and similarities between 1926, the year that Margy's Secret Mission; or, Exciting Days at Shadymere was published, and today. The girls' various jobs - freelance artist, personal secretary, department store salesgirl - are interesting, and their friendships engaging. Quite a bit of these books seem to be taken up with the sisters and their various beaus, and two of them - Helen and Margy - have more than one young man competing for their attention. These young men are always conveniently around to lend a helping hand, whether it be with heavy lifting and/or home repair tasks, or saving the day when the girls get in trouble with the bad guys they confront. That is certainly the case here, as Dale Elton, declaring that Margy's disappearance is "a job for men," rounds up a group of male friends and sets out to rescue her. Leaving aside this theme of male assistance, which some contemporary readers will undoubtedly find outdated, the story here was still quite entertaining, and is one that readers of the previous installments in the series will enjoy reading. ( )