Director Ridley Scott has added actors Idris Elba, Sean Harris, and Kate Dickie to the cast of his new sci-fi thriller Prometheus. It isn't clear which characters they will be playing at this time.

Ridley Scott also spoke about the lengths he's taking to keep the Prometheus storyline a secret. He had his cast members sign secrecy agreements, and the only way they can read the script is if they came to his office and read it there. Here's what the director had to say.

"I was insistent that the script not leak onto the internet, where it gets dissected out of context, which spoils it for everyone."

Ridley Scott also revealed a bit more about the story, and said he is using the James Bond stage at the legendary Pinewood Studios in London.

"It's the story of creation, the gods and the man who stood against them. It's not a small film. I'm using the giant James Bond 007 stage at Pinewood and six other sound stages to film it."

Production will start on Prometheus in three weeks. Director Ridley Scott did confirm that Prometheus is not a prequel to his 1979 classic Alien, although a report from January suggests that several Alien aspects will be featured in Prometheus, such as the space jockey and the DNA from xenomorph aliens, which are found during an archaeological dig.