Overview: A Doctor Who devotee, a boxing aficionado and a London Underground expert battle it out this week.
Overview: Baz Ashmawy picks the brains of three more ultimate fans, quizzing a self-proclaimed Eurovision enthusiast who hopes to score more than nul points, a Sherlock Holmes expert who's all clued up about the Baker Street detective and a contestant hooked on fishing. Up for grabs is a prize of the winner's choosing.