came to the rescue of their father after undergoing many dangers in the cliff caves.
The third volume of the series, "The Mystery of the Old Mill," which precedes the present book, relates the efforts of the Hardy boys to run to earth a gang of counterfeiters operating in and about Bayport and their efforts to solve the mystery surrounding an abandoned mill in the farming country back of Barmet Bay.
Frank Hardy, a tall, dark-haired boy of sixteen, was a year older than his brother Joe, and usually took the lead in their exploits, although Joe was not a whit behind his brother in shrewdness and in deductive ability.
Mrs. Hardy viewed their passion for detective work with considerable apprehension, preferring that they plan to go to a university and direct their energies toward entering one of the professions; but the success of the lads had been so marked in the cases on which they had been engaged that she had by now almost resigned herself to seeing them destined for careers as private detectives when they should grow older.
Just now, however, detective work was farthest from their thoughts. Frank and Tony Prito were engaged in some complicated maneuvers on the parallel bars, Joe was taking a boxing lesson from Biff Hooper, and Phil
