Characters in The Clue of the Broken Blade

Frank Hardy

Also in Crawling with Zombies, Deadly Strategy, Time Bomb, At All Costs, Break-Up!, Deception on the Set, A Figure in Hiding, The Twisted Claw, Showdown at Widow Creek, The Disappearing Floor

Joe Hardy

Also in Crawling with Zombies, Deadly Strategy, Time Bomb, At All Costs, Break-Up!, Deception on the Set, A Figure in Hiding, The Twisted Claw, Showdown at Widow Creek, The Disappearing Floor

Ettore Russo

Chet Morton

Also in The Disappearing Floor, The Mystery of the Flying Express, The Melted Coins, The Sign of the Crooked Arrow, The Secret of the Lost Tunnel, The Wailing Siren Mystery, Secret of Pirates' Hill, Mystery of the Desert Giant, The Viking Symbol Mystery, The Vanishing Thieves

Fenton Hardy

Also in The Twisted Claw, The Flickering Torch Mystery, The Secret Panel, The Secret of Skull Mountain, The Blackwing Puzzle, Mystery of the Desert Giant, The Mystery of the Spiral Bridge, The Jungle Pyramid, The Firebird Rocket, The Crowning Terror