The Tetryon-Plasma can also be ejected behind the Runabout. This engine grants a +32 bonus to your Starship Warp Core Potential. The Yellowstone comes with an advanced Tetryon-Plasma Engine. Smaller than a starship but larger than a shuttlecraft, the Yellowstone is the newest Runabout in the Federation line. Today’s FREE Federation C-Store item is the Yellowstone Runabout! To end of our Summer Event with a bang, we are excited to announce that we will be giving away FREE C-Store items this week! As we will feature something different every day, you won’t want to miss out!