A Swiftly Tilting Planet is the third book in the Time Quintet. In A Wrinkle in Time, Meg, Calvin, and Mr. Murray had all the adventures. In A Wind in the Door, it’s again Meg and Calvin with the addition of Meg’s former principal (Charles Wallace’s current principal). Book three finally lets Charles Wallace start adventuring! He also gets a unicorn to ride around on.
The Murrays get a shocking phone call at Thanksgiving dinner. There’s a dictator in Patagonia (I think) who wants to bomb everyone. Calvin’s mom basically charges Charles Wallace with saving the world. It’s a little weird, because she calls CW Chuck, and she yells out a rune that messes with the electricity.
There was a lot of back and forth between time and location, and CW had to prevent something, which would prevent the impending bomb from being launched.
Meg, who is now married to Calvin and pregnant with their first child is also tangentially involved in CW’s adventure. She’s sitting in her old room in the attic at her parent’s house, petting their newly acquired dog, and “kything” with CW. It’s basically mental telepathy that they’ve been doing on and off since they were children. They got much better at it.
CW basically has to go inside four different people in different times and places, and prevent a “might have been” from happening. There are multiple bad guys in this story too, of course. There are mythical creatures that try to stop CW’s journey and rip him off his unicorn. Then there are bad guys in the timelines he travels to that need their past changed. I liked this one! It was nice to see another Murray kid get into the time travelling action!