While on Safari in East Africa, Clyde Beatty runs into a loincloth wearing boy, Baru, and his pet ape Bonga.

She was found by High Priest Dagna as a child and declared to be Joba's goddess as part of his quest for power.

Meanwhile, the unscrupulous Durkin and Craddock notice the green diamond Baru is wearing and follow them to plunder the city for similar jewels.

Darkest Africa contained the first use of the flying special effects that Republic would go on to use in future serials, such as the acclaimed Adventures of Captain Marvel.

This serial also showcased examples of the studio's model work that would be one of the factors in its future reputation and success.

[1] Cline wrote of this serial, that "some of the finest photography of Beatty's animal training techniques ever seen were numbered in this production.