This episode marks the first appearance and visual description of Gallifrey in the new series. Time Lords are seen in their most memorable series attire (from the Tom Baker period onwards), as well as the domed city, often seen in the Big Finish Audios, and the Wilderness from "The Invasion of Time."

The Doctor: That's him...he's Prime Minister. The Master is Prime Minister of Great Britain.

Sharon Osbourne: I'm voting Saxon; he can tick my box any day.
McFly: We're voting Saxon. Come on, Harry!
Ann Widdecombe: Mr Saxon is just what this country needs. And he's handsome, too.

The Master: Doctor.
The Doctor: Master.
The Master: I like it when you use my name.
The Doctor: You chose it. Psychiatrist's field day.
The Master: As you chose yours. The man who makes people better; how sanctimonious is that?

The Master: (to President Winters) Anything I can do? I could make the tea or isn't that American enough? I dunno, I could make grits. What are grits anyway?

Jack: What do you say I use this perception filter to sneak up behind him and just break his neck?
The Doctor: Now that sounds like Torchwood.
Jack: Still a good plan.
The Doctor: He's a Time Lord, which makes him my responsibility. I'm not here to kill him. I'm here to save him.

The Master: So, Earthlings. Basically, erm, end of the world!...Here. Come. The Drums!

The Doctor: The Toclafane...what are they?
(The Master bends closer)
The Doctor: Who are they?
The Master: Doctor, if I told you the truth, your hearts would break.

The Master: Shall we decimate them? That sounds good, nice word, decimate. (to the Toclafane) Remove one tenth of the population!

The Master: And so it came to pass that the human race fell and the Earth was no more. And I looked down upon my new dominion. As Master of all. And I thought it...good.

The Doctor refers to Mr Saxon/The Master as "Prime Minister of Great Britain." The offical title of the PM is Prime Minister of the United Kingdom (of Great Britain and Northern Ireland).

President Arthur Winters refers to himself as "President Elect of the United States of America". This title would indicate that he had been elected President but had not yet been sworn in or taken office. In that case there would still be the outgoing President serving out the remainer of his term and he would be the one who would have made first contact.

The Valiant skyship bears more than a blatant resemblance to Cloudbase, the aerial fortress of SPECTRUM from Captain Scarlet and the Mysterons

Harold Saxon wears a red-silk lined cloak when he meets the President. In Doctor Who the Master often wore such a cloak.