Bulldog Drummond's partner Algy is to wed.
Bulldog attends the wedding but on his return home in the deep foggy night he wanders into an old mansion of Prince Achmed in search of a telephone.
To his shock he finds a dead corpse of an old man.
Bodies keep disappearing as Drummond attempts to contact the authorities, including neighbour Captain Nielsen.
But a woman is on the case, Gwen, who is the daughter of the dead man........
* Ronald Colman ... Capt. Hugh (Bulldog) Drummond
* Loretta Young ... Lola Field
* C. Aubrey Smith ... Captain Reginald Neilsen aka Colonel
* Charles Butterworth ... Algy aka Mousey
* Una Merkel ... Gwen
* Warner Oland ... Prince Achmed
* E.E. Clive ... London Bobbie
* Mischa Auer ... Hassan