We present results of a one-dimensional simulation of the interaction of a current sheet and a supercritical perpendicular shock in a collisionless plasma. The low-field region of the current sheet passes through the shock, allowing, for a short time, the complete reflection of the incident flow at the transition of the magnetic field to its downstream value. The counterstreaming ion beams relaunch the shock, while the low-field region remains downstream. The plasma in the low field region is unshocked but develops a complex multistream configuration, which in time develops to a more uniform distribution. We discuss the implications of the simulation results for observations within the magnetosheath and of active current sheets upstream of the bow shock. ¿ American Geophysical Union 1988