This book was a Father's Day gift from my wife. Polster is a German mathematician and author of my favorite YouTube channel, "Mathologer", where he explains difficult mathematical concepts using easy to follow colorful graphics and witty monologue. In "Q.E.D.", he outlines 25 or so mathematical proofs, each occupying one page of written proof and another page of graphics. I didn't just glance at the proofs and look at the pictures. I did my best to digest and comprehend the logic behind each proof. Occasionally this required re-reading the same page multiple times, making the 58-page book feel more like 125. Diminutive in physical stature, it is one of six books in the Sciencia Series which publishes small books with big ideas. It had all the makings of a 5-star book for this math geek, but it contains one glaring weakness, the no-so-glaring presentation. The font size is exceedingly small, and the pictures are grayscale. That is not a recipe to capture the imagination of the casual reader. As someone who loves the vivid Mathologer videos, I am used to big, bold, colorful displays. This book falls short of the lofty standards I have come to expect from Polster. The content was there, but the presentation was blasé. Sadly, I can only give it 4 stars.