In Service of The Master

The Master — originally called Koschei and known by many other temporary aliases — was a renegade Time Lord and the Doctor's arch-nemesis.Like all Time Lords, Koschei was taken for his initiation at the age of eight. During the ceremony in which he gazed into the Time Vortex through the Untempered Schism, Koschei went mad, which was not uncommon, as when Time Lords saw the Untempered Schism they either "went mad or ran away".This malady manifested itself as the constant drumming he heard ever after, worsening with time. ... Play well,and have fun!