Boy (Johnny Sheffield) is out riding an elephant in the jungle with Cheeta the chimp by his side when he hears an aeroplane flying overhead and calls for Tarzan (Johnny Weissmuller) who is swimming nearby. The plane drops a canister with a parachute attached, and it floats down to be caught on the branches of a tree. Surmising that Jane has sent it, they set about opening the canister inside which they find a letter from her, which Boy reads out: she wishes them well, but requests Tarzan bring her medicine for the troops fighting in the war...
This was the second film in the Weissmuller Tarzan series not to feature Jane, Maureen O'Sullivan having opted out of the franchise for pastures new, though that did not stop the script from making Jane the impetus for her partner to get out into the desert for this instalment's adventure. This was generally considered one of the craziest of the Lord of the Jungle's movies, apparently made in a hurry after the previous one, Tarzan Triumphs, was a hit due to its wartime propaganda, though while Nazis are the bad guys this time around, this was not quite as heavyhanded on the war aspect.
Nevertheless, Tarzan did have to negotiate his way around a couple of devious spies, Hendricks (Otto Kruger) and Straeder (Joe Sawyer), who actually have him put behind bars for a long stretch of the middle section of the movie. This meant quite often the film was carried by both Boy (and Cheeta, of course) and the female lead, who this time round was Jane substitute Connie Bryce, a magician and performer doing her bit to entertain the Arabs. She was played by former child star Nancy Kelly, who garnered an Oscar nomination over ten years later in The Bad Seed.
She didn't get a nomination for this, mainly because this type of B-movie was not the thing to bother The Academy, but she was certainly a bright spot here. With a wealth of slangy dialogue which made her perfectly of her time and endearingly quaint to modern eyes, she proves plucky in the face of death, both when she is threatened with execution and later on when some wild beasts loom large in the plot. She meets Tarzan and Boy when they "save" her from being sawn in half: she was demonstrating her act for her bearers, but Tarzan gets the wrong end of the stick and chases them away, leaving her to team up with him.
Connie also has an important message to impart, hidden in a bracelet given to her by a sheik which will reveal the true nature of Hendricks and Straeder to the authorities, but it does not quite go to plan. Even at just over an hour, the filmmakers managed to resort to padding this out with an acrobatic act from Cheeta, during which Kelly sings a song, but to be fair this was what the series' fans were expecting. What they might not have been expecting was the last twenty minutes where things get even more presposterous as Tarzan and the gang wind up in a large desert oasis to secure the fruit from which the medicine is made. It was evidently decided to turn this into a "Lost World" affair, so the characters are not only menaced by the requisite lion, but man-eating plants, dinosaurs, and most memorably a huge spider which amusingly chomps on one of the baddies. Not exactly Tarzan's finest hour, but it was... interesting. Music by Paul Sawtell.