The Power of Three

There have been many ways to invade the Earth, and the Doctor has seen them all – or so he always thought. And then the human race wakes up one morning and discovers the world has been overrun by… “very small cubes”, which then proceed to… do nothing at all. A plan is afoot, humanity is endangered – but by what and how and, above all, when? Thus begins the Year of the Slow Invasion.