In a game of Blacksmith versus Diamond, an outrageous suggestion from Johnny ends in disaster when the teams are challenged to bet on the hardest naturally occurring substance on Earth.

A scientific investigation into lip reading and how we decode speech leads to some hilarious misunderstandings.

Victoria and Johnny investigate the science behind whether a student can drink a pint upside down quicker than a Slinky can go down the stairs.

And the teams find out what happens if you pit a rugby player against a fire hose in an exciting finale.