I'll try to keep this short since it's my fourth post of the day. Just getting a little behind on reviews and need to catch up.
In Tarzan's Desert Mystery, Jane's still in London. No update on how her mom's doing, but she's stuck there because of the war and is making the most of her time by working in a military hospital.
She writes a letter to Tarzan asking him to send her a jungle remedy that will help her patients, so Tarzan, Boy, and Cheetah leave home for a distant jungle where Tarzan knows he can get the plants.
To get to this other jungle, the trio has to cross a desert. There they meet an unscrupulous European racketeer who's using his influence with a local sheik to make huge profits at the expense of his oppressed workers. The sheik's son is onto the racketeer though and is trying to work with a rival sheik to end the oppression, using an American woman as a messenger.
I like that the standard Weissmuller-Tarzan formula is finally broken here and we get a spy story instead of the usual morality play about civilization's encroachment on nature. Not that there's anything wrong with that morality play, but it's nice to see something different.
Tarzan takes a back seat for most of the movie to the various desert characters and their scheming. I thought for a bit that he might become a supporting character in his own movie, but once everyone else has made enough of a mess of things, it falls to Tarzan to straighten things out and save the day.
The desert makes for an exotic change of setting for the series, so even though this isn't a classic episode by any definition it's a nice counterpoint to the rest of the Weissmuller films. By itself it's a fairly disposable movie, but it serves a great purpose in the context of the rest of the series so far.
It even achieves awesomeness at the end when Tarzan and his friends -- with the bad guys hot on their trail -- reach the other jungle and have to find the medicine while battling bad guys, carnivorous plants, and giant spiders and lizards.