Richard Hammond's Brain Reaction

Victoria Coren Mitchell and teammate Desiree Burch go head-to-head with Johnny Vegas and Kiell Smith-Bynoe. As always, the teams are ably assisted by comedian and science geek Ria Lina.

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.

Victoria Coren Mitchell and teammate Guz Khan go head-to-head with Johnny Vegas and Kiri Pritchard-McLean. And, as always, bringing the science smarts is comedian and brain box Ria Lina.

In a baffling experiment that pits a strongman against an egg, Richard gets more than he bargained for when the strongman attempts to lift him above his head. Johnny is left red-faced after an investigation into our sense of touch puts him in a compromising situation with Kiri. Former tennis pro Miles Maclagan joins the teams to demonstrate the incredible speed of his serve. And in an explosive game of Dynamite versus Booze, Victoria and Johnny try to work out which will do the best job of blowing up a shed.

David Baddiel, standing in for Johnny Vegas, goes head to head with Victoria Coren Mitchell. Guests Bobby Mair and Lou Sanders join the fun, while comedian and brainiac Ria Lina tries to keep things on track.

In a game called Ham versus Hamster, a heated discussion about gravity and freefall nearly ends in a fight. Lou employs some outrageous techniques in a bid to raise David's heart rate.

The teams meet Britain's tallest man and former Harlem Globetrotter, Paul 'Tiny' Sturgess, as he takes on a weather balloon, and Bobby gets very worked up over whether a woman can run faster than fire. If you want to know the answer to this experiment, you'll have to tune in.

In this riotous series finale episode, Victoria Coren Mitchell and teammate Robin Morgan pit their grey matter against Johnny Vegas and Thanyia Moore. And keeping proceedings scientifically relevant is comedian and clever woman Ria Lina.

The science of swallowing comes under forensic scrutiny in: How many hot dogs can you eat in 30 seconds? Johnny and Victoria experiment, somewhat reluctantly, with iced water, needles and electricity in a test of their dexterity. Thanyia and Robin show off their pumping action skills to find out what can take the most pressure. And in an explosive ending, the teams deconstruct a hipster's breakfast to discover if it's dangerous or just plain irritating.