My Film Synopsis Idea

I was thinking that the general plot of the film would revolve around a box that everyone wants for some reason but the viewer themselves don't see what is inside the box until the end of the film. This idea I think fits nicely with the thriller genre as there is a sense of mystery and enigma as the viewer wonders what is inside the box. The film is given an edge to it as people would even kill for the box rather than just steal it. This would be shown in the first scene someone would kill there best friend for the box. Inside the box is the key to eternal power but no one know's where the door is. The killer now has the box and is trying to find the door. Other people find out about the box (main protagonist, criminals, other people) and are hunting down the killer. However what they do not know is that the killer is actually trying to find the door to destroy the box but he's going through anything to stop people obtaining the box and eternal power.

The film opening itself would be set in a woodland area or park. I think that it would be shot in a grey filter to make everything look grim (just incase it's a sunny day.) The opening would contain a man trying to bury the box and another man coming from behind him, killing him and taking the box. I don't think I would show the killer's face. I'm debating putting a narration over the scene just to describe the history of the scene, but I would want to create more questions than answers so it doesn't explain the scene just gives the viewer some context.