Fenton Hardy

Frank Hardy

Father and eldest son, with Fenton often involving Frank in detective work as a trusted partner.

Red Jackley

Fenton pursues Red Jackley as the prime suspect in the tower robbery, leading to a cat-and-mouse chase.

Joe Hardy

Father and younger son, with Joe assisting Fenton alongside Frank in investigations.

Ezra Collig

Chief of Police Collig collaborates with Fenton Hardy on the case, sharing information and resources.

Hurd Applegate

Fenton interacts with Hurd Applegate, the owner of the tower, regarding the stolen securities.

Detective Smuff

Smuff is jealous of Fenton's superior detective skills and often tries to undermine him.

Chet Morton

Chet, a friend of the Hardy boys, interacts with Fenton as a respectful acquaintance.

Perry Robinson

Perry Robinson is the son of Mr. Robinson and a suspect, with Fenton questioning him.

Slim Robinson

Slim Robinson, another son of Mr. Robinson, is interviewed by Fenton as part of the case.

Con Riley

Officer Con Riley assists Fenton Hardy with police procedures and local knowledge.

Harold Morley

Harold Morley is a business associate or witness questioned by Fenton regarding the theft.

Frank Hardy

Father and eldest son, with Fenton often involving Frank in detective work as a trusted partner.

The Speed Demon

The boys' father, an internationally famous detective, who sent them on an errand to deliver legal papers.

Chet's Auto Horn

Teaches his sons about observation and deduction, linking the theft to a possible red-haired thief.

The Mansion Robbery

Hired by Applegate to handle the case; examines the safe and finds no fingerprints.

The Arrest

Mr. Hardy attempts to mediate, suggesting that more evidence might turn up before an arrest is made.

IX: Red Hair

Receives the clue from his sons and plans to use it to help clear Henry Robinson.

X: An Important Discovery

Provides the boys with a list of stolen jewels but reveals he has already checked pawnshops, positioning himself as friendly competition.

Mr. Hardy Investigates

Examines the wig and clothing, confirms the match, and decides to trace the items in New York City.

Days of Waiting

Travels to New York to trace the red wig, interviews the wig manufacturer and actor Harold Morley, and patiently works through dead ends before finding a clue in police records.

XIV: Red Jackley

Returns home careworn and travel-stained after tracking Red Jackley; shares findings with his sons and later confronts Chief Collig and Detective Smuff.

A Confession

Returns home with news of Jackley's confession and directs the boys to search the old tower.

XIX: The Mystery Deepens

Dumbfounded by the failed search, insists Jackley was truthful, and arranges a second thorough search of both towers despite growing suspicion against Robinson.

XX: The Flash in the Tower

Mr. Hardy tells Perry Robinson that the case is hopeless unless the loot is found, and later reiterates this to the boys.

A New Idea

Mentioned as downcast over the unsolved case, feeling his work tracking Red Jackley has been wasted.

XXIII: Adelia Applegate’s Compliment

Arranges the surprise meeting and presents the recovered loot from the gunny sack.