It's a Battle of the Duds this week on Hard Quiz.

Returning are Katharina with her expert subject, penicillin; Matt with the Isle of Wight; Marcus, who's desperate to prove he knows something about dinosaurs; and Kate, who's ready to do backflips once more over Olympic gymnast Simone Biles.

Tom Gleeson is ready to take down four contestants foolish enough to have a second try at getting their hands on the Big Brass Mug.