Frank Hardy

Fenton Hardy

Father and son, with Fenton often guiding Frank in detective work.

Joe Hardy

Brothers and close partners in solving mysteries, with Frank as the more cautious leader.

Callie Shaw

Frank's steady girlfriend, showing mutual affection and support.

Tony Prito

Close friend and frequent ally in investigations, often providing local knowledge.

Uncle Dock

Uncle and nephew, with Uncle Dock often aiding the boys with his mechanical skills.

Lester

Friend and informant who helps the Hardy boys with local gossip and clues.

Chet Morton

Loyal friend who often joins the Hardy boys on adventures, despite his cautious nature.

Sleuth

Frank's dog and loyal companion, often aiding in tracking and clues.

Fenton Hardy

Father and son, with Fenton often guiding Frank in detective work.

Joe Hardy

Brothers and close partners in solving mysteries, with Frank as the more cautious leader.

Joe Hardy

Brothers and close partners in solving mysteries, with Frank as the more cautious leader.

Uncle Dock

Uncle and nephew, with Uncle Dock often aiding the boys with his mechanical skills.

A Five Dollar Bill

Older brother, dark-haired, observant; agrees to change the stranger's bill and later discovers it is counterfeit.

Counterfeit Money

Frank is the primary loser of three dollars and feels foolish for being deceived. He examines the counterfeit bill and later reports the incident to his father.

The Hardy Boys at School

Takes the teasing in good part, discusses the motorboat purchase, and promises to play on Jerry's baseball team.

Another Victim

Notices Callie's distress, learns about Pollie's counterfeit fifty-dollar bill, and gives the bill to his father.

V: Curing the Joker

Suggests the hike and participates in the revenge prank on Chet.

The Old Mill

Leads the group and questions Stummer about the mill.

In the Mill Race

Observes the men at the mill and decides to approach the boy.

VIII: Joe's Courage

Runs to the mill for help and assists in the rope rescue attempt, showing concern for his brother's safety.

The Rescue

Frank plans ahead, races to the willows, and leans out to grab Joe and Lester, holding them until help arrives.

The New Boat

Frank is thrilled with the new boat and takes the wheel first, then challenges Tony to a race.

A Man in a Hurry

Frank pilots the Sleuth, notices the approaching storm, and becomes suspicious of the stranger's story about a train.

XII: Seasick

Frank steers the boat, devises a plan to make the stranger seasick, and ultimately knocks him out.

Paul Blum

Navigates the Sleuth through fog and recounts the capture of Paul Blum to his father.

Paul Blum

Captured by the Hardy boys after attempting to hold them up; arrested for passing counterfeit money.

XIV: Con Riley Guards a Package

Frank asks about Paul Blum and participates in the flattery of Riley, later learns of Blum's escape.

The Chase

Frank leads the pursuit, uses binoculars to track Blum, and helps capture the fugitive.

The Chase

Blum escapes jail, steals the Sleuth, and is captured after his boat runs out of gas.

A Plan of Action

Frank proposes the theory that the old mill may be a counterfeiting plant and suggests talking to Lester to verify their suspicions.

A Plan of Action

Paul Blum is safely in jail after being recaptured, but he refuses to talk about the counterfeit operation.

XVII: What Lester Said

Leads the questioning of Lester, gathering key information about the mill's operations and Dock's behavior.

XVIII: Suspicions

Observes Markel's suspicious package handoff at the train station and discusses the case with Joe; later expresses confidence in solving the case.

XIX: The Rug Buyer

Returns from school to find Mrs. Hardy distressed; questions her about the rug sale and later visits the police station.

XX: A Note of Warning

Reads the warning note and decides with Joe to investigate the old mill that night, planning to use Joe's resemblance to Lester.

At the Mill

Leads the nighttime approach to the mill, strategizing their route and coordinating the crawl across the open field.

Through the Roof

Leads the climb up the willow tree and the descent through the roof, demonstrating caution and strategic thinking.

The Alarm

Frank leads the investigation, observes the counterfeiting operation, and memorizes the New York address given by Uncle Dock.

Trapped

Leads the discovery of the counterfeiters' plant and participates in the raid.

The Reckoning

Frank recalls how he became suspicious of the mill when Uncle Dock offered counterfeit bills as a reward.