 Marguerite CourtotMarguerite | Marguerite |
 Edward RosemanFerris - a Broker (as E.T. Roseman) | Ferris - a Broker (as E.T. Roseman) |
 Bradley BarkerHal Worth [Ch. 5] / Bob Winters [Ch. 6-16] | Hal Worth [Ch. 5] / Bob Winters [Ch. 6-16] |
 William SherwoodRudolph [Ch. 6] | Rudolph [Ch. 6] |
 Julia HurleyMartha [Ch. 6] | Martha [Ch. 6] |
 Helen LindrothFrances - Marguerite's Maid | Frances - Marguerite's Maid |
 Robert VaughnGarrett - Leader of the Kidnappers [Ch. 3] | Garrett - Leader of the Kidnappers [Ch. 3] |
 Harry Edwards(as J. Harry Edwards) | (as J. Harry Edwards) |
 Anna ReaderMartha - one of Durbar's Victims [Ch. 4] | Martha - one of Durbar's Victims [Ch. 4] |
 Roland BottomleyNot listed | Not listed |
 Henry A. BarrowsBolton - Head of a Band of Crooks [Ch. 8] (as H.E. Barrows) | Bolton - Head of a Band of Crooks [Ch. 8] (as H.E. Barrows) |
| RRichard PurdonPeter Enright | Peter Enright |
| PPaula ShermanNot listed | Not listed |
| EEdwin BrandtDangler - an Adventurer [Ch. 7] | Dangler - an Adventurer [Ch. 7] |
| PPhil HardyFenton - Ferris' Partner | Fenton - Ferris' Partner |
| FFrank HollandLeo - Frances' Husband | Leo - Frances' Husband |
| FF.B. VernoyHal Worth [Ch. 4] | Hal Worth [Ch. 4] |
| WWalter McEwenDurbar - an Oriental Mystic [Ch. 4] | Durbar - an Oriental Mystic [Ch. 4] |
| OOtto NiemeyerCarlow - a Fortune Hunter [Ch. 5] | Carlow - a Fortune Hunter [Ch. 5] |
| FFreeman BarnesMorton - Carlow's Accomplice [Ch. 5] / | Morton - Carlow's Accomplice [Ch. 5] / |
| SStella JennoIrene - Bolton's Accomplice [Ch. 8] | Irene - Bolton's Accomplice [Ch. 8] |
| AA. LeverGungha [Ch. 9] | Gungha [Ch. 9] |
| EEleanor LewisAlota - Gungha's Accomplice [Ch. 9] | Alota - Gungha's Accomplice [Ch. 9] |
| LLois HowellBertha - Gungha's Accomplice [Ch. 9] | Bertha - Gungha's Accomplice [Ch. 9] |
| RR.A. BennettKagler - Bob's Assistant [Ch. 10] | Kagler - Bob's Assistant [Ch. 10] |
| JJoseph SullivanWharton - a Foreign Agent [Ch. 10] | Wharton - a Foreign Agent [Ch. 10] |
| FForrest CummingsNot listed | Not listed |
| HHassan MussalliNot listed | Not listed |
