AllMovie

One suspects that David R. Foster's novel The Oval Diamond was every bit as breathlessly exciting as the 1916 film version. Upon discovering a huge diamond in Africa, miner Daunt (Arthur Bauer) and his pretty daughter Sylvia (Barbara Gilroy) find themselves the target of virtually every thief and cutthroat in the western hemisphere. Foremost among their persecutors is Daunt's own brother-in-law, the original "smiler with the knife." Daunt and Sylvia escape to America, only to find out that the villains have anticipated this move. It is up to all-purpose hero Robert Ledyard (Harris Gordon) to rescue the heroine from her father's murderers.