1. We show that tachyons exist within Black Holes. 2. We extend Special Relativity to include left-handed (Superluminal) transformations to reference frames moving at relative velocities greater than the speed of light. This set of transformations forms a group that includes the Lorentz group as an invariant subgroup. The speed of light does not change under the transformations of this group. We find new features in frames moving at a relative speed greater than the speed of light such as length dilation, time contraction, and tachyons decaying into more massive tachyons - "reverse fission." 3. Using the (Superluminal) transformations of this enlarged group we are able to define tachyons of half-integer or integer spin. We show these tachyons are local and satisfy canonical commutation relations in light-front coordinates (the "infinite momentum" frame). Thus a standard quantization procedure is possible and a conventional light-front perturbation theory can be constructed. 4....