ORIGINAL SERIES
9 The Great Airport Mystery 1930 14 The Hidden Harbor Mystery 1935
17 The Secret Warning 1938
18 The Twisted Claw 1939
21 The Clue of the Broken Blade 1942 (have in blue)
26 The Phantom Freighter 1947
27 The Secret of Skull Mountain 1948
29 The Secret of the Lost Tunnel 1950
30 The Wailing Siren Mystery 1951
31 The Secret of Wildcat Swamp 1952
32 The Crisscross Shadow 1953 (have in blue)
35 The Clue in the Embers 1955 (have in blue)
36 The Secret of Pirates' Hill 1956 (have in blue)
37 The Ghost of Skeleton Rock 1957 (have in blue)
BLUE REWRITES
8 The Mystery of Cabin Island 1966 10 What Happened at Midnight 1967
12 Footprints Under the Window 1962
13 The Mark on the Door 1967
16 A Figure in Hiding 1965
20 The Mystery of the Flying Express 1968
26 The Phantom Freighter 1970
27 The Secret of Skull Mountain 1966
28 The Sign of the Crooked Arrow 1970
29 The Secret of the Lost Tunnel 1968
30 The Wailing Siren Mystery 1968
31 The Secret of Wildcat Swamp 1969
33 The Yellow Feather Mystery 1971
35 The Clue in the Embers 1972
BLUE ORIGINALS
43 The Mystery of the Aztec Warrior 1964
44 The Haunted Fort 1965
45 The Mystery of the Spiral Bridge 1966
48 The Arctic Patrol Mystery 1969
49 The Bombay Boomerang 1970
50 Danger on the Vampire Trail 1971
51 The Masked Monkey 1972
52 The Shattered Helmet 1973
54 The Mysterious Caravan 1975
55 The Witch-Master's Key 1976
57 Mystery of the Firebird Rocket 1978
58 Sting of the Scorpion 1979
