Curious about how chemists make entirely new chemicals from scratch? Do it yourself with a set of realistic *retrosynthesis puzzles*, where you build molecules step-by-step from simple building blocks! No single hard-and-fast answers, no equipment, no previous chemistry knowledge required! Only creative thinking and learning what makes chemistry fascinating and fun. The puzzles range in difficulty from very easy to medium to special hard problems for more experienced or more daring students. The instructors will give you hints and answer your questions about all things chemistry. Join us at the beginning for a spoken overview of puzzle solving approaches, which will otherwise be available in written form throughout.