This book is dangerous. While reading it I missed metro stops, phone calls, and sleep. I also laughed. A lot. Webcomic creator and former NASA engineer Randall Munroe returns to book form for another instalment of zany humour and absurd ideas, this time providing absurd solutions to achieving everyday tasks and solving real-world problems. From fording a river by boiling it dry using a field of 300 million electric kettles, to using a swarm of butterflies to send large data files: the solutions are purposefully ludicrous. Nevertheless, this book falls back on logical principles, giving readers both a good laugh and a gentle introduction to science, engineering, and technology.