Doctor Von Blon

Philo Vance

Von Blon cooperates with Vance as the family physician, providing medical insights while maintaining a cautious distance.

Chester Greene

Chester and Von Blon are acquaintances through the Greene household, with Chester often dismissive of the doctor.

Ada Greene

Ada has a cordial, trusting relationship with Von Blon, who cares for her health and well-being.

Sibella Greene

Von Blon attends to Sibella as her physician, but their interactions are marked by her coldness and his wariness.

Ernest Heath

Von Blon and Heath interact as professionals, sharing information about the case with mutual respect.

Philo Vance

Von Blon cooperates with Vance as the family physician, providing medical insights while maintaining a cautious distance.

Ada Greene

Ada has a cordial, trusting relationship with Von Blon, who cares for her health and well-being.

Ernest Heath

Von Blon and Heath interact as professionals, sharing information about the case with mutual respect.

Ernest Heath

Von Blon and Heath interact as professionals, sharing information about the case with mutual respect.

Sibella Greene

Von Blon attends to Sibella as her physician, but their interactions are marked by her coldness and his wariness.

Chester Greene

Chester and Von Blon are acquaintances through the Greene household, with Chester often dismissive of the doctor.

Chester Greene

Chester and Von Blon are acquaintances through the Greene household, with Chester often dismissive of the doctor.

V: Homicidal Possibilities

Von Blon enters the drawing-room and reports on Ada's condition, stating she is recovering from shock and blood loss and may be questioned soon. His manner is suave and reserved, and he treats Sibella with casual cordiality.

VI: An Accusation

Attends Ada, reassures her, and sharply rebukes Sibella for her outburst.

A Painful Interview

Calms Rex with luminal, defends Rex's innocence, and recalls a camping trip with Chester Greene where a revolver was used.

A Motor Ride

Accompanies Sibella and Ada on the drive; shows displeasure when Vance joins. His relationship with the family continues to intrigue Vance.

XIV: Footprints on the Carpet

Arrived at the house earlier; was in Sibella's room when the shot was fired; confirms the wound matches the previous murders.

XV: The Murderer in the House

Provides alibi for Sibella, stating he was in her room from before 11:00 until called by Sproot. Approves plan to replace the nurse with a police plant.

The Lost Poisons

Reports to Markham that morphine and strychnine were stolen from his medical case while he was at the Greene house.

Two Wills

His satchel of poisons (morphine and strychnine) was stolen from the Greene mansion's upper hall shortly after Rex's murder, as reported by Markham.

XVIII: In the Locked Library

Visits the Greene house, appears upset about the stolen drugs, and spends time with Sibella.

XIX: Sherry and Paralysis

Defends his diagnosis of Mrs. Greene's paralysis; discusses medical texts and agrees to arrange an expert report.

XXIII: The Missing Fact

Identified as the man who secretly married Sibella Greene a year prior.

Endnotes

Noted as an amateur photographer who used cyanide tablets, and who later discovered one missing.