"They take you to a tree and hang you by your skin. Each time you scream the evil comes out of you. Sometimes, it can take three days for your evil to be spent. Pull him up."
Start Writing, Elizabeth. Your story will never happen until you type/write those first words. You will be surprised what flows as soon as you begin and once you do, you won't be able to stop until it's finished.
An Idea will become nothing without those first tentative words.
"Paul. Greg. Brad. Now this is a tough assignment. And if this mission is successful, you will be the first men to land on Mars. This project has been the most costly yet designed by man. However, the safety and security of the crew and passengers still takes top priority. Is that completely understood?"