The world has a brand new Public Enemy Number One - and his name is Clyde Langer.

Clyde is living on the streets of London, lost and abandoned - and hiding from the Night Dragon.

Joseph Serf has launched his new SerfBoard, the must-have computer that no one can resist owning. Intrigued, Sarah Jane takes Luke and Sky to investigate what is so compelling about Serf and his business. Meanwhile Clyde and Rani take a SerfBoard to pieces, suspecting alien technology may be the answer. Everyone wants the new SerfBoard - and why not? What could be so dangerous about a computer?