Doctor Who: 10 Times The Earth Was Invaded
2. The Master Race (The End Of Time)
The End of Time saw the Master unveil a new, bizarre plan for dominating the human race - by becoming them. Using an 'Immortality Gate' to rewrite the DNA of the human race to resemble his, every human on the planet became the Master. Now following his orders, the Master Race began the next step in an evil plot to summon something out of the darkness.
Following a signal put into the Master's head he had thought to be a drumbeat, the Time Lords managed to break out of the Last Great Time War. Calling it his 'Final Sanction,' Time Lord despot Rassilon planned to bring Gallifrey to Earth and repopulate it with his people. In doing so, this would destroy everyone on the planet, but it would also bring the Time War back into the universe.
Arriving on Earth, Rassilon immediately reversed the Master's manipulation of humanity and deleted the Master Race. Humanity was restored, but it wouldn't be for long. With Gallifrey appearing in the sky, this was when the Master had to decide if he was on the side of the Time Lords or the Doctor.
In revenge for torturing him with the drumbeat for his entire life, and ruining his plans, the Master helped the Doctor send Rassilon back into the Time War. With both invasions stopped, the Doctor thought that the day was won. Instead, the Doctor was forced to absorb lethal radiation to save his friend Wilfred Mott from certain death. Exposed to it, the Doctor ended the day knowing that he had just triggered a new regeneration.