Magnus Drake was a Dalek duplicate installed on Earth by the Daleks in the wake of their failed 2180s invasion of Earth. (AUDIO: Vengeance) He served as CEO of Drake Interplanetary in the 23rd century (AUDIO: Faustian, Vengeance) and was tasked with driving Earth to create new technologies that the Daleks could harvest when they returned, (AUDIO: Vengeance) all, ironically, under the guise of improving Earth's defences against a potential repeat invasion. (AUDIO: Faustian)
Although aware of his true nature and loyal to the Dalek cause, Drake had a will of his own. By improving on the technologies that had created him, (AUDIO: Vengeance) he gained a form of immortality, growing a large number of clones of himself and downloading his memories into a computer at the end of each day of his life. If his currently-active body died, the next one would reemerge in his stead.
As yet unaware of Drake's true nature, the Master killed Drake in his office by feeding him to his own pet sharks, and stole his identity. The resurrected Drake chose to let the Master continue the charade, viewing it as an effective vacation: the Master handled the running of Drake Interplanetary in a ruthless way that Drake found quite satisfactory. (AUDIO: Prey, Vengeance)