We present a case study of the event on November 26, 2008 observed by many spacecraft located in different places in the solar wind as well as in the magnetosheath/magnetosphere. The magnetosphere was globally disturbed as it is demonstrated by a major deformation of the bow shock and magnetopause surfaces, while there was no clear cause in the solar wind (no IP shock or other important solar wind disturbance upstream of the bow shock as it observed by ACE and Wind). The event was observed by THEMIS (two probes in the dawn magnetosheath and three probes in the magnetosphere), by CLUSTER (all spacecraft in the dusk magnetosheath), and by GEOTAIL moving in the inner magnetosphere. We discuss the changes of the interplanetary magnetic field orientation, upstream parameters, a state of the inner magnetosphere as possible causes of such a huge deformation.