A trade manager named Renard Dumont makes his trading post where the rhino herd is, causing them to move into gorilla territories. Will the gorillas have to move?

Two deserters of the French Foreign Legion called Hooft and Hugo flee into the jungles of Africa. Unfortunately, their former superior, Lt. Colonel Staquait, finds their tracks and vows to follow them to the ends of the earth. Tarzan rescues the deserters from the perils of the jungle and the duo begin taking advantage of the resulting hospitality. Jane, being suspicious of the parasitic pair and their fantastic stories, decides to turn them in, only to realize who the real criminal is.

Tantor drinks water from the river and gets ill. Tarzan, Jane, and the Professor go upstream to find out what's poisoning the river while Terk tries to save Tantor. Along the way, they lose their boat and get captured by a group of natives who blame them for poisoning the river.

When Terk and Tantor accidentally spill some of the fluid from the giant flowers the Professor was studying onto a few beetles, it makes them giant themselves. To stay out of trouble, they keep it a secret. But how can you keep a couple of huge beetles a secret?

Tarzan and Jane return from a trip to the Waziri village to find the Professor missing and his camp in ruin. Jane momentarily fears the worst, but soldiers on with Tarzan in an attempt to determine her father's whereabouts and condition—a pursuit impeded by the hordes of apparently mad animals, including Terk and Tantor, destroying everything in their path and pleading for the cessation of a mysterious, unheard ringing.

The jungle is visited by the former President Teddy Roosevelt and, while on the hunt for animal specimens to study (which Tarzan heavily disapproves of), both are kidnapped by conspirators. In the process of escape, Tarzan teaches the President the importance of respecting nature, and he gains a new appreciation for it by the time he leaves, promising to bring that lesson home to America.

While the gang is setting up a surprise croquet game for the Professor, Jane encounters an ill-looking fawn. Upon touching the fawn, the soul of Queen La enters her body. Failing to return to Opar by herself, La turns to Tarzan, who senses something wrong right away. Instead, she turns to Dumont for help. Can the aid of Usula, the Waziri elder, bring Jane back before La retrieves her staff and brings Opar to life again?

The arrogant and aggressive heavyweight boxing champion "One Punch" Mulligan, along with his manager and personal journalist, visit the jungle while on safari. When Tarzan accidentally knocks One Punch out cold, the boxer is mortified and demands a "rematch", which Tarzan refuses. However, One Punch is stubborn and looks for a way to provoke Tarzan into a fight.

Hugo and Hooft use Tarzan to help them gather special ingredients for their hot sauce. The sauce, with the guys' names on the bottle, becomes popular to the French Foreign Legion, and is brought to the attention of Lt. Col. Staquait. Staquait vows to re-capture Hugo and Hooft for deserting, and succeeds eventually, resulting in the duo being sent to the Cape Doom prison. Upon attempting to free his friends, Tarzan is also captured. Jane attempts to contact the Magistrate to free Hugo and Hooft legally.

Clayton's sister kidnaps Jane, Tantor, Terk, and the Professor, placing each in a separate, deadly peril. She then injects Tarzan with a fatal poison via blowdart and informs him that the antidote lies far away on a distant mountain she's dubbed "Clayton's Peak". He, therefore, has a choice—to suffer as she had and lose those he loves, or as Clayton had and lose his own life.

A writer named Ed is in desperate need of some inspiration for his next novel. He finds it while walking down the street in the form of a newspaper article about Tarzan, "The Missing Link". He begins tracking down various leads to Tarzan's whereabouts, including Tarzan's friends and enemies. They all tell Ed of their first encounters with Tarzan, prompting Ed to head out into the jungle to find Tarzan himself.

Two sneaky men named Johannes Niels and Merkus come and want Tarzan to take them to the volcano on the other side of the jungle to look for diamonds. Tarzan agrees as long as he gets a diamond for Jane in return. Little does he realize that the men are not planning to keep up their side of the bargain when the diamonds are collected—or that his friends are following them.