Full Steam Ahead

Click, click, roll! My wheels gave a tiny twitch, and then—whoosh!—they actually started turning! I rolled right forward across the bright glowing surface. Ahead of me sat a big green circular button marked with a white plus sign. I tapped it gently with my front buffer, feeling the smooth glass beneath me vibrate. Two other train friends were right beside me on the tracks! I came to a steady stop right above the glowing button, puffing with sheer delight.