Four experts match wits and dodge witticisms from host Tom Gleeson. This week's topics: Wally Lewis, Mel Brooks, Mushrooms, and Stephen Sondheim. Only the hardest will survive. Play along with the hashtag Hard Quiz!

Tom has the questions, but do his guests have the answers? Self-proclaimed experts on Olivia Newton-John, Collingwood FC, Garlic and Top Gun put their knowledge to the ultimate test.