When Marlon Brando finally arrived in Manila to complete his portion of the shoot, Coppola was upset to discover he was overweight. The director combated the problem by dressing Brando in black and only filming his face. Meanwhile a taller actor doubled for him to give him more height.

“My Kurtz was a man who saw the truth,” screenwriter Milius says of how he wrote Kurtz. “He was mad, but he saw the truth. He was destroyed by the truth, burnt out by the truth.”

Together, Brando and Coppola attempted to craft a decent ending for the film. But as Coppola struggled with the task during a hiatus from shooting, disaster struck – Brando was threatening to keep his $1m advance and drop out of the film altogether.

“Are they seriously saying Marlon would take a million dollars and then not show up?” Coppola is seen stressing in making-of doc Heart Of Darkness: A Filmmaker’s Apocalypse. “Imagine here I am with about 50 things that are quasi in my control, like the Philippine government and the helicopters that they take away whenever they feel like...

“All I’m asking is for people to allow me to start a little later, and I know it’s all my fault. The picture’s bigger than I thought, it’s just gigantic.

“I personally, as an artist, would love the opportunity to finish the picture up until the end, take four weeks off, work with Marlon, re-write it and then in just three weeks do the ending. I think I could make the best film that way.”  For Brando’s representation and the studio, though, postponement wasn’t an option...