Two friends are spending a week, day/night crossing London inside a black cab and reading a science fiction book. In the story their imagination is so powerful that they are able to become the characters from the book and re-create new and better realities around them in 3D.
The book is about the the story of X - a little germ entering someone's mouth. X's vision is somewhat blurred. Its vision is in 'distorted 3D'. The mouth is the ultimate frontier between the inside of a creature and the rest of the universe. It is the border control. There is a long process before reaching the heart of the body. X aims to re-produce itself into the heart of the body just like a little mouse. When inside the body, X the germ can see, feel and breathe exactly what the creature's body sees, feels and breathes.