num_pages: 160
description: Investigating the disappearance of an air taxi pilot, Frank and Joe uncover evidence of sabotage that points directly to the missing man's passenger, millionaire Ian Fairbanks, who is connected to a national conspiracy.
language: English
title: The Hypersonic Secret
titlecomplete: The Hypersonic Secret (Hardy Boys, #135)
genres: Classics, Childrens, Mystery
ratings_count: 87
series: The Hardy Boys
publisher: Aladdin