From Star Wars to 2001: A Space Odyssey, from Jurassic Park to Doctor Who and everything in between, this series heads to the frontiers of space and science for the definitive television history of science fiction. What if we could travel not just through space, but through time itself? If you could travel through time, would you change the past or the future? What if you found it couldn't be changed? What price does the time traveller - and the people they are closest to - pay? This is a journey from H. G. Wells' The Time Machine through ideas like The Grandfather Paradox and The Butterfly Effect to the professional time traveller that is the ever popular Doctor Who.