Absolutely mind-blowing. If you have ever taken a geometry class and don't mind old-timey language or brain-bending, READ THIS BOOK. 

This is a fictional story that gets you thinking about the fourth dimension. MC is an elitist, two-dimensional Square. 

Part 1 is Victorian *satire* (I was progressively more appalled until I remembered this, and then it became hilarious. I had to fetch paper towels when I made my husband spit out his tea). Part 2 is A Wrinkle in Time for grown-ups 🤩 

It was work, but it was SO worth it. I had to look up a number of words. I had to stop and ponder. I filled 4 pages of my little journal with quotes from this book, and then started putting them in my phone to write down later so I could keep reading. 

It was written by a theologian, and it shows. There are TONS of biblical references, and several oh-snap moments to stop and meditate on the nature of God and his relationship with Man, if you like. The author added a preface later including a caution that it isn't an exact allegory, though, so I wouldn't stress about everything lining up perfectly. It's just (really good) food for thought.