 The cluster spacecraft observed multiple dipolarization fronts, DFs, and the magnetotail during a substorm event. These DFs were embedded in the bursty plasma flow and moved earthward and downward. They contained intense electric fields, parallel and perpendicular currents, and enhanced plasma wave activity. The DFs were thought to be generated by transient reconnection processes and subsequently moved towards the earth. This article was authored by S. Y. Huang, S. Y. Huang, M. Zhou, and others.