The Doctor states that looking into the time vortex causes some Time Lords to go mad , implying that event to have been the cause of the Master 's actions and the four-beat sound of drums , which the Master calls the `` drums of war '' .
The Doctor states that looking into the time vortex causes some to be inspired , some to run away ( which he did ) , and others to go mad ; it is implied that the latter is what happened to the Master .