Hunting for Hidden ____
Vol. 5 (1928)
__________ Under the Window
Vol. 12 (1933)
The _____ Road Mystery
Vol. 6 (1928)
The Tower ________
Vol. 1 (1927)
The Hidden ______ Mystery
Vol. 14 (1935)
The House on the _____
Vol. 2 (1927)
The Missing _____
Vol. 4 (1928)
The ____ on the Door
Vol. 13 (1934)
The Sinister ________
Vol. 15 (1936)
The Mystery of _____ Island
Vol. 8 (1929)
The Great _______ Mystery
Vol. 9 (1930)
The Secret of the _____
Vol. 7 (1929)
The Secret of the Old ____
Vol. 3 (1927)
While the _____ Ticked
Vol. 11 (1932)
What Happened at ________
Vol. 10 (1931)
Airport
Cabin
Caves
Chums
Cliff
Clock
Footprints
Gold
Harbor
Mark
Midnight
Mill
Shore
Signpost
Treasure
Correct!
Incorrect
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