Joe Hardy

Frank Hardy

Brothers and constant partners in solving mysteries, with Frank often taking the lead.

Fenton Hardy

Father and son, with Joe looking up to Fenton and assisting in investigations.

Snackley

Joe actively works against Snackley, showing bravery and defiance.

Chet Morton

Chet and Joe are good friends, often joking and working together on cases.

Fenton Hardy

Father and son, with Joe looking up to Fenton and assisting in investigations.

Frank Hardy

Brothers and constant partners in solving mysteries, with Frank often taking the lead.

Frank Hardy

Brothers and constant partners in solving mysteries, with Frank often taking the lead.

Snackley

Joe actively works against Snackley, showing bravery and defiance.

Chet Morton

Chet and Joe are good friends, often joking and working together on cases.

The Haunted House

Frank's younger brother, fifteen, fair-haired; rides with Biff as passenger; eager for adventure.

The Storm

Supports Frank's decision to investigate, though initially unnerved by the shriek.

III: Empty Tool Boxes

Rescued from debris by Frank, finds his own tool box also empty.

The Chase in the Bay

Finds his tool box also empty, agrees with Frank about the mystery, and witnesses the boat explosion with horror.

The Rescue

Assists Frank in rowing and carrying the rescued man, nearly slipping on the rocks.

Snackley

Joe participates in recounting the day's events and helps carry the wounded Jones upstairs.

Bound and Gagged

Accompanies Frank to the farmhouse and helps investigate the strange scene.

The Stolen Witness

Accompanies Frank, helps free the Kanes, and discusses the kidnapping with his brother.

The Strange Message

Joe shares Frank's concern and eagerly agrees to search for their father.

X: The Vain Search

Assists Frank in the investigation, agrees to organize friends for the search of the Polucca place.

The Cap on the Peg

Participates in the search, expresses puzzlement at the changed appearance of the Polucca house.

XII: Pointed Questions

Supports Frank, questions Redhead, and examines the cap.

A Plan of Attack

Participates in the debate and sarcastically questions the police's haste.

XIV: Private Property

Cheerfully shouts goodbye to the threatening stranger.

Smugglers

Agrees with Frank's deduction; swims ashore with Frank to pursue the smugglers.

The Secret Passage

Accompanies Frank, slips into the water but continues; helps steady Frank after he falls into a deep hole.

The Chamber in the Cliff

Accompanies Frank, helps move boxes to reveal the hidden door, and hides with Frank behind silk-draped boxes.

A Startling Discovery

Whispers to Frank during the tense wait, shares the realization of their peril, and listens intently to the voices beyond the door.

XIX: Captured

Assists in freeing his father by trying to untie knots, and prepares to fight the smugglers.

XX: Dire Threats

Bound and downhearted; expresses fear of being sent to China.

Quick Work

Freed by his father, then cuts Frank's ropes; participates in trussing up Malloy.

Into the Haunted House

Extinguishes the candle to plunge the staircase into darkness and assists in opening the attic trapdoor.

XXIII: Rescue

Fights in the darkness, punching a smuggler during the confusion.

The Roundup

Leads officers through the trapdoor and underground passages, and helps coordinate the capture of escaping smugglers.

The Mystery Explained

Adds details about the half-wit's shrieks and the danger during the rescue.