Mayor Margaret Blaine, also known as Blon Fel Fotch Passamer-Day Slitheen, seems to think the Doctor is some kind of fool.
She’s wrong of course, as the Doctor proves. Repeatedly.
She distracts him and poisons his drink. He switches their glasses.
She fires a poison dark from her finger. He effortlessly catches it.
She breathes poison gas at him. He retaliates with breath freshener.
Finally she resorts to pleading for compassion, freedom.
But she’s a killer; she killed the woman whose skin she’s wearing, and she’ll never change. The Doctor understands her only too well.
Maybe they’re not so different.