DOCTOR: When you built that monstrous Domovoi, you certainly pulled out all the stops, Ernest. You can’t kill her, can you?

TIERMANN: Nothing can do that.

MARTHA: Except the Voracious Craw. And the Domovoi knows that. That’s why she’s gone bananas.

DOCTOR: Is that a medical diagnosis, Doctor Jones?

MARTHA: Too right it is!