Below are some of the stories that have come up as potential premise, when a new Indiana Jones movie has been announced.
...The Fate Of Atlantis
Supported by the psychic Sophia Hapgood and pursued by the Nazis, Indiana searches for the sunken kingdom of Atlantis and must prevent the Third Reich from obtaining its advanced technology, to prevent them from inflicting it on mankind..
...The Infernal Machine
A physicist interested in alternate dimensions seeks to to find the god Marduk on another plane of existence. Indiana returns with Sophia (now C.I.A.), in a race to stop him obtaining the ancient, Babylonian machine parts that will allow him to do this.
...The Mystery Of Mount Sinai
A Mayan pyramid gives detail to a weapon so formidable that anyone who has it, could decide the fate of the world. Of course those nasty Nazis are in pursuit, potentially making World War II the shortest battle in history if they get their evil hands on it.
...The White witch
Indy and Gale Parker search for a hoard of ancient treasure, that also includes the coins that were meant to fund the spread of Christianity. Throw in witchcraft, Excalibur and a bunch of hardcore villains and you have another exciting adventure.
...Staff Of Kings
A friend of Indy's draws him into another saga, when he announces that he has a lead on a missing colleague. When the friend and a relative also disappear, Indy is thrown into another adventure, where there is a hunt for Moses' sea dividing staff.
...The Sargasso Pirates
Adrift with a band of pirates on the Sargasso sea, a long sought treasure seems to have already been claimed and protected by restless spirits, who may turn out not to be as mythological as everyone thought. Your timbers might just shiver.