THE STORY In response to a letter from Jane, who is in England nursing British troops, Tarzan and Boy trek across the desert looking for jungle plants to be used in creating a malaria serum. On the way they save a Jaynar, a wild horse, from a German, arrive at an Arab city and .rescue a stranded American magician, Connie Bryce (Nancy Kelly), When they reach Bir Herari, they meet Hendrix, who is really the Nazi, Heinrich, whom Connie is on a mission to expose. Heinrich arrests Tarzan as a horse thief. Heinrich and his cronie, Strader, follow Connie who is delivering a message to the sheik's palace. The Germans kill the sheik's son, Prince Selim (Robert Lowery) and frame it on Connie who is sentenced to hang. Tarzan escapes and summons the stallion Jaynar and during the resulting stampede, Tarzan is able to rescue Connie and take her to a nearby jungle where Tarzan fights off prehistoric monsters to obtain the fever medicine. He battles a maneating plant and throws the Nazis to be killed by a giant spider. 

The film went through a number of re-writes and re-shootings which resulted in the finished project being substantially different from what the director  originally started with. The pressbook synopsis gives an idea of what changes were made in the process of shooting:  Tarzan, Boy and Cheta the Chimpanzee come out of their jungle to the fringes of the Sahara Desert seeking a curative herb for Mrs. Tarzan. In the desert they acquire a new companion, a beautiful stallion named Jaynar. They also learn that Nazi secret agents are striving to instigate trouble in the territories of two important sheiks, one of whom sends a beautiful American chorus girl, Connie Bryce, to warn his neighbor against the head agent, Hendrix. The sheik’s son, Prince Selim, also tries to warn his father, but is not believed. Meanwhile, Connie clashes with Hendrix and his henchmen. The clash brings Tarzan and the girl together, and they join forces in a common cause. Before she can deliver her message, however, Prince Selim is killed by the conspirators, who succeed in getting Connie tried for the crime, and condemned to die. Tarzan is also thrown into prison. Boy and Cheta aid Tarzan to escape. On Jaynar the stallion, Tarzan rides through crowds gathered to watch Connie’s execution, and rescues her. They hide in the desert, but the girl is captured by Hendrix, while Boy goes on to seek aid from the neighboring sheik. Tarzan sees this sheik, obtaining from him proof of Connie’s identity and the enemy plot. On his return, he finds Connie again about to face the gallows. He dashes in, confronting the enemy agents with the damning evidence of their guilt in the presence of the sheik. This forces Hendrix’s hand. He gives word for the uprising to start. Boy, meanwhile, is guiding a column of the neighbor sheik’s men to the rescue. Tarzan’s audacity and quick action temporarily saves the situation at the sheik’s palace. He also prevents the insurrectionists from ambushing the column led by Boy. A pitched battle between the combined forces of the sheiks, aided by Tarzan, and the enemy forces, ensues. The latter are routed. Connie bids a fond farewell to her new desert friends and departs for London, bearing with her the medicinal herbs for Mrs. Tarzan.

Variety Tarzan's Desert Mystery doesn't miss a thing with its quota of Nazis and gruesome animals, plus the usual Tarzan jungle scenes. The film should lure the juves in droves to the dual setup to which the pic is headed. The picture opens with Johnny Weissmuller, Johnny Sheffield, and the chimp Cheta, setting out across a desert to find a cure-all herb ordered by Mrs. Tarzan in London. On the way they run into Nancy Kelly, an American vaudeville performer who is on her way to warn a local sheik that Otto Kruger and Joe Sawyer are a couple of Nazi agents trying to stir up trouble. Things look tough for Tarzan and his crew when he is accused of stealing a stallion intended for the sheik and Miss Kelly is framed on a murder charge and sentenced to be hanged.  Miss Kelly, who has replaced Maureen O'Sullivan, as the femme lead in this Tarzan picture turns in a workmanlike performance as an American magician. Weissmuller, Sheffield and Cheta are per usual. Kruger just doesn't belong as a Nazi. The film is nicely paced and photography highly effective. Tarzan's Desert Mystery is the second Sol Lesser production based on the popular Edgar Rice Burroughs character, none too adroitly handled in story pattern but very passable fare for Saturday matinees. Latter reels abound in suspenseful action, prehistoric monsters coming in for their moments and the heavy meeting his well-deserved end under tentacles of a giant spider. Nancy Kelly is Johnny Weissmuller's running mate in this one as the character of Jane, Tarzan's real mate, is still among the missing. She's mentioned as being still in England nursing soldiers and Johnny Sheffield enacts his usual role of Boy. And of course, there's Cheta, the chimp, to steal scenes. The story is motivated by Jane writing Tarzan, asking him to send her malaria medicine which he extracts from certain jungle plants. En route to the jungle where this certain growth is found, Tarzan must cross a desert, and it is here that the ape-man is hurled into a plot which carries him into an Arab city, where much of action unfolds. He saves Nancy Kelly, an American showgirl embroiled in a frame-up which gets her sentenced to be hanged, and in subsequent unreeling, Otto Kruger, Nazi agent, and his henchman, Joe Sawyer, are killed. The film concludes with Miss Kelly leaving Tarzan and Boy to return to civilization. This is the picture which Lesser remade, after finishing it once. The film still is ragged but it possesses attributes which will make it stand up as a dual supporter, the last two reels compensating for slowness which distinguishes first half of picture. Weissmuller, sans fights with wild animals, does not appear in as much footage as in past Tarzan films, and the picture suffers accordingly, with too much attention being directed to the character portrayed by Miss Kelly. Actually, as the film stands, Tarzan plays a secondary character. The actor turns in a highly acceptable performance, however, as does Boy. Cheta particularly is a standout in greater footage than formerly. Miss Kelly seems out of character in her role, but she is quite adequate, and Otto Kruger and Joe Sawyer are sufficiently menacing. Robert Lowery is in for an interesting bit as son of the sheik, a part enacted by Lloyd Corrigan. William Thiele handled direction from the script by Edward T. Lowe, and Kurt Neumann acted as associate producer for Lesser. Both did capable jobs with what was at hand. The music score by Paul Sawtell as directed by C. Bakaleinikoff added to the general acceptability of film. Hans Peters and Ralph Berger did the atmospheric art direction job, and Victor Gangelin and Stanley Murphy followed suit with their interiors.

The Hollywood Reporter

With a steady unfailing market that has endured for many years, any adventure of Tarzan is an assured box office property. And there has been no more popular player of Edgar Rice Burroughs' lord of the jungle than Johnny Weissmuller. Consequently, it must be reported that the Sol Lesser production of Tarzan's Desert Mystery is in the bag right now as a film attraction. But is also should be recorded that the entertainment falls below standard for the perennial series. It makes too many compromises and wanders too far from the domain where Tarzan is seen to his best advantage. A letter from Jane, Tarzan's mate absent from his side to do her bit as a nurse in the war that is shaking the outside world, sends him to obtain a badly needed fever remedy. Boy begs to go along, and of course, Cheta, the chimpanzee is not to be denied the trip. On the desert they must cross to reach the place where the required medicine grows, Tarzan incurs the wrath of a German agent by refusing to allow him to capture a wild horse. He also meets an American girl magician who is carrying a message to the powerful sheik of an Arab tribe. This message reveals the German's duplicity. So both she and Tarzan are marked as enemies of the Nazi. Twice Cheta saves the day, once by stealing the message the girl carries, again by swiping turbans from Arabs that Tarzan may fashion a rope to escape from jail. Almost another picture starts in the final reels when Tarzan must fight off prehistoric monsters to obtain the fever cure. There is a seriously intended sequence with a giant spider that is almost as amusing as the delightful comedy contributed by Cheta. Weissmuller's performance of Tarzan is as colorful as always, and Johnny Sheffield admirably portrays Boy. Nancy Kelly rises splendidly to her role of the girl magician, a square-shooting American trouper whom it is a pleasure to meet. Otto Kruger is the German, Joe Sawyer his henchman, Lloyd Corrigan, the kindly sheik, and Robert Lowery, his ill-fated son. Direction by William Thiele is no more than acceptable because of the story meanderings, but the combined photography of Harry Wild and Russ Harlan is responsible for some handsome desert and jungle effects. Kurt Neumann served as associate producer, and the art direction is a dual credit to Hans  eters and Ralph Berger. Paul Sawtell's music score is rather ordinary.

Motion Picture Daily

The Latest Tarzan film is strictly kid stuff. The picture is one long string of events designed to stir up the youngsters to no end. Things happen so fast and furiously that Tarzan is scarcely given the time to draw a deep breath as he applies his strength and cunning to upsetting the plans of a Nazi agent to cause trouble between two desert tribes. The film, produced by Sol Lesser, has been given headlong direction by William Thiele. Edward T. Lowe concocted the screenplay from a yarn by Carroll Young. Johnny Weissmuller plays Tarzan in his usual stolid manner. Nancy Kelly enacts the chorus girl adequately. Johnny Sheffield has lost none of his appeal as Boy. In Otto Kruger, the role of the Nazi agent is in good hands. Joseph Sawyer, Lloyd Corrigan, Robert Lowery are others who merit a good word. Cheta the Chimp steals the show every time she's around.

Ref: Geoff St. Andrews' Johnny Weissmuller Site

TARZAN'S DESERT MYSTERY We learn in the first scene that Tarzan is almost entirely illiterate, when a letter from Jane is dropped from airplane onto the escarpment. Boy has to read it to him, and since Jane asks that Tarzan NOT bring Boy to find certain healing plants to be used in the war effort, Boy lies and pretends that she wrote for him TO take Boy along, across the desert to the wilderness area. 

Tarzan frees an Arabian stallion and the horse has the unusual tendency of animals to be submissive to him, and it adopts him as a master, so we get to see Tarzan riding a horse in this movie. This makes Weissmuller look even more suitably Burroughsesque than usual. Another great scene is during the rescue of the horse, where he shoots an arrow from afar, pinning a rifleman's wrists together. 

At an oasis we meet Connie, an American adventurer who speaks in the comical current colloquillisms of the forties. This is very reminiscent of some of Burroughs' own Tarzan book characters, and she has a very engaging personality. So engaging, in fact, that Boy tries earnestly to convince her to come live at the tree house with him and Tarzan. I am not sure exactly where that would be going, but Tarzan gets up and walks out, demonstrating that he is concentrating upon Jane at that time.

In the Arab city, another case of the reduction of distances in Africa in these movies, since Tarzan and Boy can reach this city across a desert in what appears to be a few hours or days at the most, we get to see the full potentials of the ape named Cheeta. Cheeta gives a show for the inhabitants at the arrangment of Connie and Boy. Cheeta walks a tightrope back and forth, many times, backwards, hopping on one foot while on the rope, turning somersaults on the rope, going blindflolded, etc. It is an impressive act, especially since it is presented in such as way as to suggest there are no special effects used. It appears to be an incredlbly talented APE, no mere monkey. It dawned upon me that Cheeta is an APE, not Nkima, and thus more akin to Akut. It would be fascinating to ask Johnny Sheffield if he ever had any problem with Cheeta biting him, as I have heard other Tarzans had a problem with. It would appear from these films that Boy and Cheeta were on very close, affectionate terms.

Boy tries to be  a good influence upon Connie. When Connie puts Boy to bed for the night, Boy insists that she say prayers with him as Jane taught him. Here we have what I call "Boy's Prayer":

Dear Father who art in heaven/ Watch over me this night/ Protect me from evil/ Bless Tarzan and deliver him from those who would harm him/ Bless Jane so far away and the soldiers she nurses/ PS God bless Connie too/ Amen.

Tarzan gives a couple of ape cries-- once when he calls elephants to rescue him from a man-eating plant, and once when he calls to the corraled horses to break free. This latter cry is actually some kind of strange whistle. Again we see Tarzan riding into the village square on a horse, this time to rescue Connie from the gallows. It is notable that virtually no real Arabs were cast in this film-- even the young handsome Prince appears to be a Hollywood pretty boy, with almost blond hair. Also, no comically phoney Arab dialects as we have become accustomed from watching the more modern Indiana Jones/Mummy movies.

The climax of the movie takes place in a strange area deep in the jungle, something very much like Pal-ul-don. Here we see dinosaurs having mortal duels, and Boy is caught in the web of a giant spider that would make the spiders in the Conan stories pale in comparative size. The spider is somewhat hokey, but I was not able to tell clearly exactly how they handled the special effects of the dinosaurs, which came off quite realistically. I think what they did was to have a giant lizard of some kind, and I mean a really big lizard like a Gila monster or some other type even larger, fight a crocodile to which they had affixed a ridge crest to make it look like a dinosaur. it had to have been a very large lizard since it was as big as the crocodile, and they locked their jaws together in battle. I do not think that it could have been stop motion animation.

Finally I want to comment upon another great Cheeta scene. Tarzan is imprisoned in a tower, and there are no bars on the window since it is a sheer drop to the ground. However, there are carved designs up the side, and Tarzan SHOULD have been able to climb down it. The Tarzan of the books definitely would have been able to climb down. Still, at least they show Cheeta climbing down it and then back up, giving some kind of idea of exactly HOW it is that apes are able to climb sheer cliffs so well.

All in all a very enjoyable entertaining film.

~ Steve Allsup