According to a recent interview by MTV, It seems Mr. Lucus is still having trouble putting together a script for IJ4. I don't blame him. After discovering the power of the Ark and immortality with the Holy Grail, it seems an almost insurmountable task to develop a script which could eclipse those plots. What could possibly inspire IJ to get off his rocker for IJ4? The Urim or Thummin or "Lights and Perfections."
These rocks are not just your average good luck charms. Aaron used these stones together with a breastplate to judge the 12 tribes of Israel. Joseph Smith, the Mormon Prophet, used them to translate the Gold Plates into the Book of Mormon. The stones would allow one to see the answer to any question. The power of these stones is much greater than "glass looking." These seer stones can be considered the ultimate Google search engine. They may have been used by Solomon and the source of his great wisdom.
There is more to the story. From LC we know that IJ grew up in Utah and would be aware of Mormon mythology. According to this mythology, a number of other artifacts reside with the Seer Stones such as the unsheaved sword of Laban, breastplate of Laban, gold plates with its sealed portion, and director known as the Liahona. The gold plates and other artifacts were given back to an immortal being names Moroni and placed in the treasure room presummably in the Central American Commorah.
This mountain is the site of the final battles of 2 ancient American civilizations at the time of their annihalation. The artifacts are guarded by 3 immortal beings known as the 3 Nephites. The Antagonist could be a Spanish Colonialist (A wannabe Cortez). I would not use a renegade polygomist fundamentalist (i.e. Warren Jeffs) because he is a rather disturbing character.
Setting for the movie would include the Mormon Granite Vaults in Little Cottonwood Canyon Utah and Up-state New York and Ohio and Ilinois and other early Mormon church sites. IJ would visit these sites in search of clues. Other major settings includes the jungles of Central America and Ruins of Palanque which is believed to be the site of the Ancient Book of Mormon capital Zarahemla.
More information on Mormon mythology can be obtained by contacting FARMS at Brigham Young University Dept. of Ancient Scripture. IJ will also have to know Mayan Heiroglyphics. Alan Christiansen at BYU is an expert Ancient Mayan Art Historian.
I think the public is ready for this kind of plot. I just can't think of an archiological find that would eclipse finding the Holy Grail and the Ark. Solomon choose the gift of wisdom over power, wealth and immortality.