The Doctor and Jo are attending the inauguration of Felicity Morgan as Prime Minister of Samael. During the speech, she's shot, and the pair rush to help, helping her assistants and two masked extra-planetery dignitaries get her home. When there, she releases a burst of energy, rejuvenating herself from the brink of death in a manner the Doctor recognises all to well. But, at the end, she keeps the same face.
The Minister, as she now calls herself, is a renegade Time Lord, and ex-CIA agent who was given the ability to regenerate without changing form, through a link with her TARDIS - now disguised as her house. The Doctor finds this scandalous - the process is highly unstable, and one slightly hiccup could lead to her being rendered insane or dead - but the Minister claims it to be perfectly safe, and better than the trauma of changing bodies at every trauma. Jo's chat with her assistants reveals she's regenerated several times before, each time her personality changing subtly. As the Minister for War, she was more aggressive, while as the Minister for Foreign Affairs, she was more diplomatic. The Minister decides she's fit for duty, and heads back to make her speech. During the redo, however, she begins to stutter and lose her words, the regeneration failing. Once again, the Doctor and Jo rush her home, hoping to stablilse her condition. The Doctor rushes off to check on the TARDIS itself, and Jo is eventually sent after him by one of the diplomats from earlier, as he claims the Doctor is in danger. She rushes off, and finds the Doctor perfectly fine. The Minister's TARDIS, however, has been sabotaged. Precise enough sabotage to indicate someone with intimate knowledge of a TARDIS.
With the Doctor and Jo sidetracked,the diplomat approaches the Minister, hypnotising her back to her Minister of War mindset, and convincing her to show him Samael's weapons stores. The Third Doctor and Jo catch them just as they get there, and without his diplomatic mask, the Doctor now recognises his eternal foe, the Master. He rigged up the assassination of the Minister to force her to play her regenerative hand, and sabotaged her TARDIS to take advantage of the mental confusion it would induce, all so he could gain access to Samael's weapons and conquer the nearby planets. Jo is able to appeal to the Minister's inner good nature, and snap her back to her senses. The Master manages to escape, but with his plans thwarted.
Back at the Minister's TARDIS, her post-regenerative trauma has calmed, and the Doctor has installed mental blocks that will prevent such sabotage from hurting her again, but in exchange, the Minister has forgotten the process of how to regenerate without changing. She's reassured, however, by Jo's words from earlier - no matter what face she wears, she's still the person she was.
The Same Face contains examples of the following trope:
- Call-Forward: The Minister gained her regenerative abilities from the the Celestial Intervention Agency.
