High resolution x-ray observations of the Crab Nebula show the existence of a well-defined bright torus. A straightforward estimate suggests the inadequacy of the conventional model for the pulsar-wind terminal shock. A resolution to this difficulty is given in this report; it is proposed that the pulsar-wind shock can only be "thermalized" in a collisionless fashion and hence the shock transition is bound to be broad. A dynamical scenario is given regarding how the shock "thermalization" should proceed, and it employs the excitation of solitons that serve as the energy carriers in transporting the pulsar wind energy afar and depositing the energy when certain conditions in the background plasmas are met. A necessary condition for such an energy-deposition process to occur is that the charateristic wave speed decreases with distance, a condition that can hold in the Crab Nebula.
