Brother detectives Frank and Joe return to dangerous Black Bear Mountain to help locate a scientist gone missing from a remote research station.

Bibliographic Details
Main Author:	Dixon, Franklin W.
Format:	BOOK
Other Format:	EAUDIO EBOOK
Language:	ENGLISH
Published:	Aladdin 2020
Series:	Hardy boys adventures book 20
Subjects:	Mystery and detective stories Brothers Mountains Wilderness areas Missing persons
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