Which subject will win Tom Gleeson's Big Brass Mug for its expert contestant? Crime writer Agatha Christie, Nazi dictator Adolf Hitler, the musical Jesus Christ Superstar or online game Fortnite.

Battle of the Duds! Tom Gleeson faces four people foolish enough to have a second try at the Big Brass Mug with their expert subjects of diamonds, social psychology, Novak Djokovic, and the Australian Dung Beetle Project.