1-The Secret of the Old Clock 1930

2-The Hidden Staircase 1930

3-The Bungalow Mystery 1930

4-The Mystery at Lilac Inn 1930

5-The Secret Of Shadow Ranch 1931

6-The Secret of Red Gate Farm 1931

7-The Clue in the Diary 1932

8-Nancy's Mysterious Letter 1932

9-The Sign of the Twisted Candles 1933

10-The Password to Larkspur Lane 1933

11-The Clue of the Broken Locket 1934

12-The Message in the Hollow Oak 1935

13-The Mystery of the Ivory Charm 1936

14-The Whispering Statue 1937

15-The Haunted Bridge 1937

16-The Clue of the Tapping Heels 1939

17-The Mystery of the Brass-Bound Trunk 1940

18-The Mystery at the Moss-Covered Mansion 1941

19-The Quest of the Missing Map 1942

20-The Clue in the Jewel Box 1943

21-The Secret in the Old Attic 1944

22-The Clue in the Crumbling Wall 1945

23-The Mystery of the Tolling Bell 1946

24-The Clue in the Old Album 1947

25-The Ghost of Blackwood Hall 1948

26-The Clue of the Leaning Chimney 1949

27-The Secret of the Wooden Lady 1950

28-The Clue of the Black Keys 1951

29-The Mystery at the Ski Jump 1952

30-The Clue of the Velvet Mask 1953

31-The Ringmaster's Secret 1953

32-The Scarlet Slipper Mystery 1954

33-The Witch Tree Symbol 1955

34-The Hidden Window Mystery 1956

35-The Haunted Showboat 1957

36-The Secret of the Golden Pavilion 1959

37-The Clue in the Old Stagecoach 1960

38-The Mystery of the Fire Dragon 1961

39-The Clue of the Dancing Puppet 1962

40-The Moonstone Castle Mystery 1963

41-The Clue of the Whistling Bagpipes 1964

42-The Phantom of Pine Hill 1965

43-The Mystery of the 99 Steps 1966

44-The Clue in the Crossword Cipher 1967

45-The Spider Sapphire Mystery 1968

46-The Invisible Intruder 1969

47-The Mysterious Mannequin 1970

48-The Crooked Banister 1971

49-The Secret of Mirror Bay 1972

50-The Double Jinx Mystery 1973

51-Mystery of the Glowing Eye 1974

52-The Secret of the Forgotten City 1975

53-The Sky Phantom 1976

54-The Strange Message in the Parchment 1977

5-5Mystery of Crocodile Island 1978

56-The Thirteenth Pearl 1979

57-The Triple Hoax 1979

58The Flying Saucer Mystery 1980

59The Secret in the Old Lace 1980

60The Greek Symbol Mystery 1980

61The Swami's Ring 1981

62The Kachina Doll Mystery 1981

63The Twin Dilemma 1981

64Captive Witness 1981