A letter from Jane, who is nursing British troops, asks Tarzan's help in obtaining a malaria serum extractable from jungle plants. Tarzan and Boy set out across the desert looking for the plants. Along the way they befriend a stranded American lady magician.

• Sol Lesser Productions
• Johnny Weissmüller
• Nancy Kelly
• Johnny Sheffield
• Otto Kruger
• Joe Sawyer
• Lloyd Corrigan
• Robert Lowery
• Frank Puglia