The Talosian civilization once flourished on the planet's surface and was capable of warp half a million years ago. Unfortunately, more than 200,000 years ago, they fought in a cataclysmic war, so much of the planet's surface became uninhabitable. The rest of the population now lives underground and has telepathic abilities. They create their own telepathic world, where they trap anyone who is close to their planet. Therefore, a strict quarantine is imposed around Talos until a tool is developed to capture the difference between reality and dream.
UPF REGULATION No. 7: No member of the Fleet may visit the planet Talos IV at any cost and under any circumstances. This Regulation suppresses Regulation 6. Any breach of this Regulation shall be punishable by death.