I was in an underground train station and a mine-cart was moving very slowly on the tracks. Somewhere by the track there was a sign that read: “This goes up to 555 km/h. How lucky will you get?” I sat into the cart and it slowly started to accelerate. By the time I got out of the tunnel and out into the open, I was speeding over the tracks. There were large groups of people walking along and next me on what was a very sunny day. I was afraid of losing control at the speeds I was going at but I also knew that the moment I stopped, i wouldn’t be able to regain my initial momentum.