This is the first episode of the 2005 series to mention Gallifrey, the Doctor's home planet, by name.
This episode reveals that the Doctor's pockets, like the TARDIS, are "bigger on the inside."
This episode reveals that huon particles are an ancient form of energy present in the Heart of the TARDIS.
The Doctor (David Tennant
) uses his sonic screwdriver to manipulate a cashpoint, exactly as he did in the 2005 episode "The Long Game
Donna: Who are you?
The Doctor: I am the Doctor. And who are you?
The Doctor: Human?
Donna: Yeah. Is that optional?
The Doctor: It is with me.
The Doctor: Weird, you're not special, you're not powerful, you're not connected, you're not clever, you're not important...?
Donna: This friend of yours, just before she left, did she punch you in the face?
The Doctor: Only a madmen talks to thin air and trust me, you don’t want to make me mad.
The Empress of the Racnoss: Prepare your best medicines, Doctor-man!
The Doctor: Oh but I'm not from Mars.
The Empress of the Racnoss: Then where?
The Doctor: My home planet is far away and long since gone. But its name lives on...Gallifrey.
The Doctor: It was all in the job title: head of human resources.
Lance: This time, it's personnel.
(Lance and the Empress of the Racnoss start laughing)
The Doctor: (referring to the TARDIS) I've got to park her properly or she might drift off to the Middle Ages.
Donna: Will I see you again?
The Doctor: If I'm lucky.
Donna: Just promise me one thing. Find someone.
The Doctor: I don't need anyone.
Donna: Yes, you do. Because sometimes, I think you need someone to stop you.
The Doctor: Yeah.