This quantum mechanics primer will accompany the reader from school to university. The formal basis of the subject is briefly introduced, and the reader is then quickly given the tools to start solving problems as diverse as quantising motion in potentials, quantum mechanical tunnelling, muon catalysed fusion, pair production, motion in nanostructures, and the interference of particles as waves. Chapters 1–3 guide the transition from school to university, and develop the skills and understanding that are typically tested in admissions to university physics, maths and engineering degrees. Chapters 2–5 cover university-level quantum mechanics courses, up to the second year of a typical physics degree. All problems can be answered and marked on the Isaac Physics online platform. Registration is free and gives both students and teachers personalised support through a sophisticated online marking system for all problems. This second edition is a co-publication between Periphyseos Press and Cambridge University Press.