66 million years ago, a ten-mile-wide object from outer space hurtled into the Earth at incredible speed. The impact annihilated the dinosaurs, along with three-quarters of the other species on the planet. But what if this catastrophe was the sign of something greater: an opening vista onto the interconnectedness of the universe itself? This is the story of the astounding forces that underpin our existence; a horizon-expanding tour of the cosmos that unifies what we know about the universe with new thinking. From the far-flung reaches of space, the makeup of the universe and our solar system's place within it, to the mysterious and elusive stuff of dark matter and how it affects life here on Earth.