"A Tale of Time City" by Diana Wynne Jones

Despite the title evoking A Tale of Two Cities, this book has functionally nothing to do with Dickens. Instead, it involves time travel.

How this book's time travel works is there are "Stable Eras" and "Unstable Eras." This obviates confusion about "but what if you go back in time and change history?", because history is always changing in the Unstable Eras. Those always turn out the same way, though, so the Stable Eras (where nothing messes with history) don't get messed up. It's a good way to have time travel work, in other words.

Anyway, on to the plot! Vivian Smith is a normal girl being evacuated from London during the Blitz. She's supposed to be staying with a cousin in the country, but instead she gets abducted by aliens two teenage boys from Time City. They think they're saving the city from disintegrating or something (I don't actually remember what was going to happen if the city finally wore out the patch of weird altered time it was sitting on) by getting the person who's going to mess it up out of history, but they kidnap the wrong person.

(I have a sneaking suspicion none of that made any sense.)

Then they have to pretend Vivian is supposed to be there, which she isn't, long enough that they can figure out who's screwing with history. And, ideally, stop them. Plus there's a group of four MacGuffins that keep Time City anchored to history so it doesn't go flying off to nowhere and get lost, and people keep stealing them.

Were this a videogame, I'd rate it: E10+ for mild and indirectly described violence.

I'm giving A Tale of Time City 4 stars, one for each MacGuffin.

Favorite lines:

I actually do have... well, it's more of a favorite page, but still. Since it's so long, I've put it on my brand new Very Long Quotes Page, as quote 1. Vivian's despair over her miserable failure to translate it, and Dr. Wilander's sarcasm, are quite hilarious. I actually went back and read that page several times because it made me laugh so much.

(Endnote: The time travel in this isn't really dwelt upon, and nobody even bothers trying to explain any of it. I think that's part of the reason it doesn't invite speculation and/or plot holes as much as in other books.)