In Tarzan's (Johnny Weissmuller) jungle, his son Boy (Johnny
Sheffield), finds gold, but has no idea what to do with it ... until his
mother Jane tells him about the value gold would have in
civilisation ... & soon enough, boy grows so curious about
civilisation that he one night leaves mum & dad to go there ... but he
doesn't get too far, since soon enough, he meets native boy Tumbo (Cordell
Hickman), who asks him to help his dying mother ... but boy can do
precious little, mother dies, & Tumbo's tribe think it's Boy's fault
& want to sacrifice him - when an expedition, led by benign professor
Elliott (Reginald Owen) stops by to save Boy.
Unfortunately though, while Elliott & his assistant O'Toole (Barry
Fitzgerald) are honest men, their guides Medford (Tom Conway) &
Vandermeer (Philip Dorn) are less so, & when they hear about the gold
found in Tarzan's jungle which Tarzan won't let them take just like that,
they first kill Elliott, then lure Tarzan away & take Jane & Boy
hostage, to be released only in exchange for the gold. Reluctantly Tarzan
has to give in.
But when he shows Medford his gold, Medford even shoots him ...
Then the whole expedition makes its getaway with Jane & Boy
captives & plans to soon come again to mine the gold ... but of course
their escape route leads through some wild natives' territory, & soon
enough too, the whole expeition finds themselves captives of especially
savage natives ... all but O'Toole, who has made a getaway from the group,
& with the help of Tumbo found Tarzan, who has not been quite killed
but left on an inescapable narrow cliff - inescapable until O'Toole helps.
Then Tarzan proceeds to attack the natives, who are canoeing down some
crocodile infested river, by one by one tipping over their canoes (&
thus feeding the crocodiles), & this way, freeing Jane & Boy.
& to really finish the natives off, Tarzan drives his friends, a horde
of elephants, into the river to cause maximum havoc.
In the end, Tarzan, Jane and Boy are reunited, & of the expedition
only O'Toole has survived, & he is allowed to travel back to
civilisation with a bag of gold ...
In this fifth installment in MGM's Tarzan-series, the formula - evil
white men are entering Tarzan's realm & threaten to destroy his world,
but in the end the jungle (= natives) turn against them, & Tarzan has
to turn against the natives to save Jane (& Boy) - has grown
considerably stale, so the whole story of the film as such holds little
interest & is in fact interchangeable with those of the previous
movies. It's only when the particularly gruesome natives start torturing
their prisoners & when Tarzan fights the natives in crocodile infested
waters & calls in his elephants for help that the film comes into its
own, unfortunately though that's too little, too late.