Mystery of the flying express /
by Franklin W. Dixon.
- New York : Grosset & Dunlap, [1970]
- 177 p. : ill. ; 20 cm.
- Hardy boys mystery stories ; 20 .
- Dixon, Franklin W. Hardy boys mystery stories ; 20. .
After the new hydrofoil they are guarding is stolen, the Hardy boys face frequent danger in solving a mystery involving criminals who operate by signs of the zodiac.