This week, Matt and Jason dive back into the book and get deep into the history of industrial chemistry and its impact on the 20th Century. Topics include: problem solving strategies for multiple unit processes, AIChE Concept Warehouse, hypothetical ITFH merchandise, periodic table belt buckles, recycle loops, the Haber-Bosch Process, ammonia and fertilizer, the Fischer-Tropsch process, oil and the Battle of Stalingrad, Geography Bees, zombies, Harry Potter, air conditioning and refrigeration, and authors' voices in textbooks.