Tension mounts as Gyles Brandreth presents the first of the semi-finals of the quiz without questions.

Contestants have their breadth of knowledge tested to the limit as they battle it out to impress the show's experts. Two teams are given their topics and then have just one hour to pool their knowledge before facing the Knowitall experts. The categories are sport, entertainment and science.

The winners go through to the grand final and are one step closer to the prize of 15,000 pounds and the title of Britain's biggest Knowitalls. Show less