The Sentinel is probably the best known short story by Arthur C. Clarke. Famous for being the one that 2001: A Space Odissey was somehow based on. When they asked me: "would you do some science fiction illustration?", I didn't imagine I was about to illustrate this! It was quite a bit of a challenge. While I love sci-fi and loved to illustrate this story, it gave me little to work with, so I had to get inside the characters and find the things the story doesn't tell you.