 Nils AstherDr. Julian Karell | Dr. Julian Karell |
 Helen WalkerEve Brandon | Eve Brandon |
 Reinhold SchünzelDr. Kurt van Bruecken | Dr. Kurt van Bruecken |
 Paul CavanaghDr. Henry Latimer | Dr. Henry Latimer |
 Konstantin ShayneDr. B.A. Vishanoff | Dr. B.A. Vishanoff |
 Leyland HodgsonDr. G.B. Albertson | Dr. G.B. Albertson |
 Edmund BreonSir Humphrey Brandon | Sir Humphrey Brandon |
 Morton LowryAlan Guthrie | Alan Guthrie |
 Matthew BoultonDetective Inspector Ned Garth | Detective Inspector Ned Garth |
 Eustace WyattInspector Lawson | Inspector Lawson |
 Brandon HurstSimpson | Simpson |
| AArthur MullinerSir John Aldergate | Sir John Aldergate |
 Aminta DyneLady Minerva Aldergate | Lady Minerva Aldergate |
 Edward FieldingColonel Ashley | Colonel Ashley |
 Forrester HarveyHarris | Harris |
 Ernie AdamsPorter | Porter |
| NNorman AinsleyButler in Brandon's Home | Butler in Brandon's Home |
| DDonald GallaherTicket Agent | Ticket Agent |
 John SheehanExpressman | Expressman |
| EEdward CooperLiveried Servant | Liveried Servant |
 Reginald SheffieldArt Expert at Party | Art Expert at Party |
 Gerald Oliver SmithPharmacy Clerk | Pharmacy Clerk |
| AArthur BlakeMan | Man |
 Ted BillingsMan Sleeping on Bench | Man Sleeping on Bench |
| GGeorge BroughtonMorgue Official | Morgue Official |
| WWilson BengeMorgue Official | Morgue Official |
 Harry CordingBobby | Bobby |
 Al FergusonBobby | Bobby |
| RRobert CoryBobby (uncredited) | Bobby (uncredited) |
 Frank HagneyBobby (uncredited) | Bobby (uncredited) |
