Merdyn (a grumpy wizard), Rose (definitely not his 21st century sidekick) and Bubbles (the talking guinea pig) have a new catastrophe on their hands... An enormous warrior has kidnapped Rose's brother and time-travelled back to the Dark Ages. Rose finds her brother very annoying, but she knows they should probably rescue him. Can Rose and Merdyn succeed without causing historical mayhem? And will Bubbles ever stop pooing everywhere?