The paper reports ISEE 1 and 2 plasma observations in the plasma sheet near 15 RE radial distance for the 1054 substorm on March 22, 1979. Noteworthy features are plasma sheet thinning and the brief appearance of rapid tailward flows after substorm onset, strong earthward flows (superimposed on dawnward convection) at the beginning of plasma sheet expansion and a quieting of all plasma properties at substorm recovery. Much of the time, however, plasma flows are small and switch directions. In particular, no strong flows are observed during neutral sheet crossings. Two-dimensional velocity distribution functions show a complex behavior, with several plasma components often coexisting and at times streaming in opposite directions. The interpretation of the observations in terms of the formation of a neutral line earthward of and close to ISEE at substorm onset is tempting, but three-dimensional spatial effects as well as rapid temporal changes have to be invoked to obtain consistency.