That was a horribly crude description, but the commodore had yet to meet anyone who could describe it any better without resorting to pure math models. For her purposes, it worked well enough to visualize the galaxy of the FTL-traveler as consisting of concentric rings of dimensions; by moving "higher" in multi-dimensional space, a ship translated itself into rings with shorter and shorter radii, which meant that the same absolute velocity seemed higher in relation to normal-space. The physicists assured her she wasn't really moving at more than light-speed, but the practical result was FTL travel.

Still, there were limitations. The multi-dee was unusable inside the "Frankel Limit," a flexible point in stellar gravity wells which varied widely depending on spectral class and vessel mass, and though one theoretically could simply translate directly from normal-space into whatever other dimension one chose to use and vice versa, it was far wiser to translate gradually from one to another.

Dimensional energy flux could be vicious, and many things could happen to people who took liberties with the multi-dee. Few were pleasant. The alpha band-the "lowest" of all-was only about twenty dimensions across. At its upper limit, the maximum effective velocity of a ship (relative to normal-space) was about five times light-speed. Higher bands offered greater effective speeds, but at the cost of increasingly unstable energy states and consequently increasing risk to the ship. And there were barriers, still imperfectly understood, between the bands that meant cracking the wall was always risky. If a ship hit the wall just wrong or with the slightest harmonic in her translation field, she simply disappeared. She went acoherent, spread over a multitude of dimensions and forever unable to reconstitute herself, a thought which broke a cold sweat on the most hardened spacehound, for no one knew what happened inside the ship. Did the crew die? Did they go into some sort of stasis? Or did they gradually discover what had happened ... and that they had become a galactic Flying Dutchman for all eternity?