I
Mentioned as arriving at the office; Jim dislikes him for avoiding war service, and he stands to benefit from the Danton fortune.
II
Visits Salter's office to examine Lakeside leases; displays arrogance and a dismissive attitude toward Jim Steele; reacts with alarm upon seeing Jim's notes on the Thirteen Gang.
III
Identified by Jim as the 'unmitigated cad' who stands to inherit the Danton millions if the missing heiress is not found.
IV
Confronts his mother about her theft, threatens her with a brain operation, and arranges the return of the bracelet.
V
Caught in his laboratory preparing to vivisect a stray dog; confronts Jim and Eunice, but is forced to release the animal.
VI
Apologizes for lying about the dog, explains his experiment, and discusses his study of faces and heads. He is attracted to Eunice but deliberately restrains himself.
VII
Forces his mother to give Eunice work, retrieves the stolen watch, and witnesses his mother's collapse at the sight of Eunice's scar.
Chapter IX
Mentioned as having many Spanish friends, speaking Spanish fluently, and being a former shipping clerk who married into the Danton family.
The Secret Will
Reacted with fury upon learning of the will, burned it, and lied about the Marquis of Estremeda; questioned Eunice about her scar.
Chapter XI
Plots to control Eunice, regrets destroying the will, and feels growing fascination with her.
XII
Mentioned as the one who gave Eunice the chocolates; Eunice considers telling him about the warning but decides not to.
XIII
Appears tired and haggard; questions Eunice about the night's events; reflects on his mother's drug addiction and his control over her; attends Lord Waltham's reception.
XIV
Referenced as the recipient of the chocolates and as someone who might not understand the meaning of the blue handprint.
The Key
Referenced indirectly through the key labeled 'D. G.'s master key', which is intended to grant access to his premises.
Chapter XVI
Confronts his mother about the will, destroys it, and forces her to lie to Eunice. He is determined to possess Eunice as a 'decoration' and threatens Jackson.
XVII
Mentioned as possibly being behind the Selengers, along with his mother.
Chapter XVIII
Returns home at midnight, prompting Eunice's vigilance.
XIX
Mentioned as plotting to make Eunice a passing amusement; Lady Mary aims to bring him and his mother to justice.
Chapter XX
Shows Eunice a photograph of the Blue Hand print, proving it is a woman's, and is absent for most of the day.
XXI
Enters in evening dress, discusses the mysterious intruder and the blue handprint, and reveals the intruder's identity as Madge Benson.
XXII
Receives a letter, is trailed by Jim, and later sends men to follow Jim.
XXIII
Questions Eunice about Jim; angrily expels Mrs. Weatherwale; fumes over the police involvement and blames Jim Steele.
XXIV
Seen driving past Jim and Eunice in the park, earlier bundled Mrs. Weatherwale out of the house.
XXVI
Revealed to have been a cruel child who burned a baby's wrist with a hot sixpence, leaving a circular scar.
XXVII
Plans to sell Danton estate quickly; manipulates situation and allows Jim to meet Eunice.
XXVIII
Senses the end approaching, plans to flee to a ranch in San Paulo, and lies that Eunice has left for Paris.
XIX
Lies about Eunice's wishes, arranges false trail to Paris, and plans to force Eunice's compliance.
The Retreat to Kennett Hall
Travels to Kennett Hall to prepare a refuge and issues orders to Villa for purchasing a yacht.
XXXI
Arranges the property transfer, secures his mother's signature, and receives a telegram from Villa.
XXXII
Reveals his predatory nature to Eunice, is struck by her, then learns from his mother that Dorothy Danton is alive and that he marked her as a child.
XXXIII
Drugs Eunice, disguises himself, and transports her to a hidden garage, planning his escape.
XXXV
Dressed as a chauffeur and without his moustache; admits he has fled Grosvenor Square and pressures Eunice to marry him, but is frightened by her threat.
XXXVI
Disguises as a woman in black, drugs and manipulates Eunice, plans escape via train interception and flight to Kennett Hall, and counts stolen money.
XXXVII
Disguised as an elderly woman, he manipulates and threatens Eunice, revealing his obsessive desire to possess her.
XXXVIII
Disguised in women's clothing, he orchestrates the escape from the train and transports Eunice to a remote house, revealing his manipulative and controlling nature.
XXXIX
Mentioned as the boss; his voice is heard speaking to someone near the pond, and his men discuss his orders regarding Eunice.
XLI
Captures Jim and Eunice, threatens and bribes Masters, confronts Eunice's insults.
XLII
Interrogates Jim, learns of Villa's death, and panics upon hearing the police know about the yacht; he decides to flee with Eunice that night.
XLIII
Frantically prepares for escape by aeroplane, dispatches Silva, tests equipment, and later shoots Fuentes when he refuses to kill Jim.
XLIV
Flees with Eunice by seaplane after killing Villa; shows panic and horror at his own act.
XLV
Reveals his ruthless nature: he drowns Bronson, threatens Eunice, and plans to flee to South America via a secret route.
XLVI
Confronts the captain after learning of the reward for his arrest; negotiates a bribe and later pays the captain a bundle of bonds to ensure his escape.
XLVII
Attempts to force himself on Eunice, is threatened by her pistol, then tricks her and assaults her until the captain stops him with a warning shot.
XLVIII
Confronts the captain, prepares poison, then decides to wait and attempt to woo Eunice during the voyage.
XLIX
Aboard the yacht Pealigo, orders the ship's name changed to Malaga, tries to prevent the captain from stopping, is put in irons, escapes and attacks Eunice, but is knocked out by Jim.
