'Indiana Jones 5' re-hires 'Kingdom of the Crystal Skull' and 'Jurassic Park' writer

David Koepp is back on board the planned fifth movie in the Indiana Jones series.

In a series of reshuffles of the movie, Koepp was replaced on the movie in June last year by Jonathan Kasdan, son of Empire Strikes Back and Raiders of the Lost Ark writer Lawrence Kasdan.

Kasdan Jr penned Solo: A Star Wars Story in 2018, and was reportedly brought on board after producers said they weren't happy with Koepp's script.

Read more: Indiana Jones 5 plot ideas

This resulted in the movie being bumped back on the Lucasfilm slate, from a plotted July 2020 release to July, 2021.

But now, he's back in the saddle, telling Den of Geek: “I actually am again. I’m working on it again. We’re still trying.

“And I think we’ve got a good idea this time. We’ll see.”

Veteran writer Koepp penned Indiana Jones and the Kingdom of the Crystal Skull, the fourth Indy movie, as well as movies like Jurassic Park, the first Mission: Impossible movie, Spielberg's remake of War of the Worlds and Sam Raimi's Spider-Man.

But his reappointment is only the latest in a seemingly indecisive pre-production period.

Talk of a fifth movie has been circulating since Crystal Skull premiered, to muted reviews, in 2008, and then re-emerging when Disney bought up Lucasfilm in 2012.

Read more: The Last Crusade was nearly a disaster

Lucasfilm's Kathleen Kennedy then confirmed plans to make a new movie in 2015, also confirmed that George Lucas would be acting as an executive producer.

A filming date was even set for April, 2019, but that came and went, with more recent reports that filming will star in April, 2020 now instead.

As for the film's 'MacGuffin', the phrase popularised by Alfred Hitchcock, but often used by Lucas when referring to the key plot point of the Indy movies, is not yet known.

Rumours that it could involve the Bermuda Triangle were rubbished long ago by producer Frank Marshall, but rumours later emerged that Kasdan had penned a script surrounding the Wałbrzych Nazi gold train.

Local legend had it a train transporting stolen gold was buried in Poland in a tunnel underground during the last days of World War II.

It's not yet known whether this could provide the backbone of the latest Indy story, but heavy excavations might not be particularly suited to Harrison Ford's grumpy archeologist these days.

The actor will be 79 in 2021.