Destiny of the Daleks

ROMANA: Yes, they taught me at school how to stop my hearts.

TYSSAN: Hearts? How many have you got?

ROMANA: One for casual, one for best.

DAVROS: I have failed!

DOCTOR: Yes. What does it feel like?

K9: coughs

DOCTOR: Do that again.

K9: coughs again

DOCTOR: Say "ah".

K9: scratchy "ah" sound

DOCTOR: Ah! Laryngitis! How can a robot catch laryngitis? I mean, what do you need it for?

DOCTOR: Hold it, hold it. Now, tell them what I've got here.

DAVROS: He is holding a primed explosive device.

DOCTOR: And one false move, and it goes right down inside his chair. I'll turn Davros and his life-support system into scrap metal. Now spack off!