George Zucco

Dr. Moriarty (archive footage)

Dr. Joseph Van Ee (archive footage)

Dr. Cameron (archive footage)

Prof. Lampini (archive footage)

self

Egyptian Ambassador (uncredited)

Father Robert Stuart

The Voice

Judge Mackenzie

H.G. Danziger

Dubocage

Judge

Dr. Fortescue

Constable of Clervaux

The Viceroy

Otto Dagoff

Palanth, the High Priest

Doc Robbin

Marquis De Carvajal

Paul Stertorius

Father Donnard

H.R. Barrett

Craxton

Dr. Josef Van Ee

Mr. Mallam

Prof. Andrew Forbes

Dr. Pavel Storasky

Detective Geddes

Bey of Aribajan

Jelke