Sometimes the Doctor is terrifyingly reckless.

Terror of the Autons, last episode, closing lines:

Re: The Master escaping them and wandering around on the Earth to make mischief again.

Jo: You don't seem very worried about it.
Three: I'm not. As a matter of fact, Jo, I'm looking rather forward to it. [kooky grin]

Uhm, dude, usualy I'm down with your death-defying wierdness, but lots and lots of people DIED from the Master's evilness. And probably more will.

...

I'm talking to a fictional character. WTF.