Torchwood2006

Gwen Cooper:
Owen and Toshiko, you didn't tell them that you were shot in the head and survived.

Captain Jack Harkness:
You didn't tell them either. Followed my lead. Keep doing that, you might just get through this.

Gwen Cooper:
But she killed you!

Captain Jack Harkness:
I can't die.

Gwen Cooper:
Ok!

Captain Jack Harkness:
But I can't. Something happened to me a while back. Long story and far away. But I was killed, and I was brought back to life, and since then, I can't die.

Gwen Cooper:
But how...?

Captain Jack Harkness:
I don't know. One day I'll find a doctor, the right sort of doctor, and maybe he can explain it, but until then...

Gwen Cooper:
Nothing kills you?

Captain Jack Harkness:
Well, it kinda freaks people out. Best if you don't say anything.