The Abzorbaloff, the monster in this episode, was created by a Blue Peter viewer as part of a competition.

Bad Wolf is mentioned.

As noted in the commentary, the acronym "LINDA" was previously used on the British children's television programme show Why Don't You?, which featured the "Liverpool Investigation 'n' Detective Agency". Russell T. Davies worked on the series for some years.

Sir Elton John appears in a video clip on Elton Pope's video diary.

This is the first Doctor Who story to feature an ampersand instead of the word "and" in the title.

According to Doctor Who Magazine #370, this episode had the working title of "I Love the Doctor."

This is the first Doctor Who story not to feature the Doctor or his companions as the main character(s) since "Mission to the Unknown" (1965), which had none of the regular cast present.

The creature that Elton sees at the start of the episode is credited as the "Hoix." Russell T. Davies notes in the commentary for the episode that the name was invented only after the episode was shot and a name was needed for the credits.

Elton Pope: That's what it did. It went "Rawwrr"! And if you think that was the most exciting day of my life, wait till you hear the rest. Oh boy.

The Doctor: (talking to the Hoix) Here boy! Eat the food! Come on! Look at the lovely food! Isn't that nice? Isn't it? Yes it is... (to Elton) Get out of here quickly - (to the Hoix) that's a boy how'd-ya-like-a-porky-choppy-then... I said run!
(Rose runs in with a blue bucket)
Rose: Aaaaahhh!!!!!
The Doctor: Wrong one! You made it worse!
Rose: You said blue!
The Doctor: I said not blue!

Elton Pope: That wasn't the first time I met the Doctor, and it certainly wasn't the last. Oh no. I just put that at the beginning because it's a brilliant opening.

Ursula Blake: His name is the Doctor.
Elton Pope: Doctor what?
Ursula Blake: That's all anyone knows.

Victor Kennedy: You met him and you froze? You stupid man!
Elton Pope: You can’t hit me, ‘cos you don’t touch. You said so. You get a rash and an itch…
Victor Kennedy: I can use this!
Elton Pope: Use that cane on him and you’ll get one hell of a smack off me! And then a good kick. Is that completely understood, Mr. Kennedy?
Victor Kennedy: Duly noted. Ursula Blake, most likely to fight back.

Elton Pope: And so it began. The impossible task. To scour the mean streets, to search a major capital city for an unknown girl. To hunt down that face in a seething metropolis of lost souls. To find that one girl in ten million.
(first person he shows Rose's photo to)
Mrs. Croot: Oh, that’s Rose Tyler. She lives just down there. Butland House, number forty-seven. Her mum’s Jackie Tyler. Nice family. Bit odd.

Elton Pope: (voiceover) I’d been trained for this. Victor Kennedy’s classes covered basic surveillance and espionage. Step one: engage your target. Find some excuse to start a conversation. But how was I going to do this? How?
Jackie Tyler: Excuse me, love. You couldn’t give us a quid for two fifties, could you?
Elton Pope: Yeah, I’ll just, uh...
Jackie Tyler: Oh, lovely, cheers.
Elton Pope: (voiceover) Step Two: without provoking suspicion, get on first-name terms with the target.
Jackie Tyler: My name’s Jackie, by the way.
Elton Pope: I’m Elton.
Jackie Tyler: Oh, you don’t meet many Eltons, do you? Apart from the obvious. (laughs)
Elton Pope: (voiceover) Step Three; ingratiate yourself with a joke or some humorous device.
Jackie Tyler: I tell you what, Elton, here we are, complete strangers, and I’m flashing you my knickers. (laughs)
Elton Pope: (voiceover) Step Four: find some subtle way to integrate yourself into the target’s household.
Jackie Tyler: Mind you, I’m only down here 'cos my washing machine’s knackered. I don’t suppose you’re any good at fixing things, are you?

(after talking with Jackie)
Victor Kennedy: Magnificent! Oh, I could kiss you. Except I can’t, of course… the eczema…
Elton Pope: I’ve even got a picture of her on my phone.
Mr Skinner: Well, that’s amazing. You’ve achieved steps one to four in precise order. How did you manage it?
Elton Pope: Well, I had to work very hard. She keeps everything very close to her chest.
Ursula Blake: That’s a hell of a chest.

Jackie Tyler: I went in your coat. For once in my life I thought, ‘I’ll pay’. I thought, ‘he’s such a nice man, he won’t accept anything, so I’ll just slip a tenner in his pocket’. And look what I found. A photograph of my daughter.
Elton Pope: No, no, no, it’s not like that. I can explain.
Jackie Tyler: I bet you can.
Elton Pope: I wasn’t being pervy or anything. I wasn’t after her. I was looking for the Doctor.
Jackie Tyler: Oh, I know that. I worked that out. 'cos it’s never me, is it?
Elton Pope: No but that’s how it started. But I changed my mind…
Jackie Tyler: Let me tell you something about those who get left behind. Because it’s hard. And that’s what you become. Hard. But if there’s one thing I’ve learned, it’s that I will never let her down. And I’ll protect them both until the end of my life. So whatever you want, I’m warning you… back off.

Rose: You upset my mum.
Elton Pope: <em>(indicates the Abzorbaloff)</em> Great big absorbing creature from outer space, and you're having a go at me?
Rose: No-one upsets my mum!

Rose: Is it me or is he a bit...Slitheen?
The Doctor: Are you from Raxacoricofallapatorius?
The Abzorbaloff: No, I'm not! They're swine, I spit on them! I'm from the twin planet.
The Doctor: Really? What's the twin planet of Raxacoricofallapatorius?
The Abzorbaloff: Clom!
The Doctor: Clom?
The Abzorbaloff: Clom, yes.

The Abzorbaloff: You’ll surrender yourself to me, Doctor. Or this one dies. You see, I’ve read about you, Doctor. I’ve studied you. So passionate. So sweet. You wouldn’t let an innocent man die. And I’ll absorb him unless you give yourself to me.
The Doctor: Sweet, maybe. Passionate, I suppose. But don’t ever mistake that for nice. Do what you want.

Elton Pope: So, there you go. Turns out I’ve had the most terrible things happen. And the most brilliant things. And sometimes… well, I can’t tell the difference. They’re all the same thing. They’re… just me. You know, Stephen King said once, he said "‘salvation and damnation are the same thing." And I never knew what he meant. But I do now. Cos the Doctor might be wonderful but… thinking back, I was having such a special time. Just for a bit. I had this nice little gang and they were destroyed. It’s not his fault. Maybe that’s what happens if you touch the Doctor. Even for a second. I keep thinking of Rose and Jackie, and how much longer before they pay the price.

Elton: But the thing is ... but what I wanted to say is, you know when you're a kid, they tell you it's all "Grow up, get a job, get married, get a house, have a kid" and that's it. Nah. The truth is the world is so much stranger than that. It's so much darker. And so much madder. And so much better.

The scene where Elton watches the Doctor and Rose flee from the Hoix involves them running around in a humorous manner usually seen in cartoon or comedy series such as Scooby-Doo or The Benny Hill Show.

Later in the episode, Elton remembers the LINDA band playing an ELO song perfectly, where earlier we had seen their actual far-from-perfect version. In the commentary it is noted his memory may not be entirely reliable, so whether events in the episode happened the way he remembers them (or at all) is debatable.