Quantum mechanics underpins modern science & provides us with a blueprint for reality itself. & yet it has been said that if you're not shocked by it you don't understand it. But is quantum physics really so unknowable? Is reality really so strange? & just how can cats be half-alive & half-dead at the same time? Our journey into the quantum begins with nature's own conjuring trick in which we discover that atoms -- contrary to the rules of everyday experience -- can exist in two locations at once. To understand this we travel back to the dawn of the twentieth century & witness the birth of quantum theory which over the next one hundred years was to overthrow so many of our deeply held notions about the nature of our universe. Scientists & philosophers have been left grappling with its implications every since.