It's a futuristic tale that takes place in the 24th Century, as a father explains the ground rules for "Jaunting," a form of teleportation the family will be using shortly to go to Mars. The key is that travelers must be under anesthesia for the short journey, or terrible things happen to the mind of those being jaunted around the solar system. Time stands still and one's brain implodes with too much time to think in an absence of external stimulation. Bad things happen.