Maud Gregaards travels to China in search of a fabled treasure said to have belonged to the Queen of Sheba. Once there, she is taken captive by an evil man and nearly killed in the belief she is a witch.

Rowland falls sick with leprosy while Mac Allan is captured by the Maharajah, who offers Irene a deal: one night with him in exchange for letting Rowland to be cured. She accepts, but tries to commit suicide.

A black African avenges his father by murdering the inspector of a diamond mine.

Thanks to the treasure of the Queen of Sheba, Maud, who now calls herself Fergusson, has become an immensely wealthy woman. The plane that rescued her and Allan Stanley from Ophir belongs to newspaper king Fletcher, who reports on the rescue operation on the front pages of his newspapers.

Through the plan hidden in Astarte's jewelry, Maud Gregaards, Kien-Lung and Consul Madsen get on the trail of the Queen of Sheba's treasure. Their search takes them to Africa, where they want to know from King Makombe the location of the Fire Mountain, near which the legendary city of Ophir, the center of the Astarte cult, is said to be.

German colonial soldiers fight against the British during World War I.

In geheimer Mission is a crime drama movie set in the year 1938. It follows the story of a group of individuals on a secret mission, dealing with crime and the challenges they face during that time.

As Madsen and Maud explore the city of Ophir, they witness an ancient ritual performed by the residents. The two are discovered, and with strangers desecrating the city's sacred ground, Maud is to be sacrificed to the goddess Ophirs, while Madsen is taken to the Sabytes, an enslaved native tribe.