The guests joining Lee Mack and David Mitchell are Rylan Clark-Neal, Sara Pascoe, Mary Portas and Paul Sinha.
Five new contestants: Iain Stirling, Joe Thomas, Lou Sanders, Paul Sinha and Sian Gibson, complete a series of tasks under the watchful eye of Greg Davies and Alex Horne.
Joe Thomas struggles with the definition of a mammal, Iain Stirling devises an explosive chemistry experiment and Sian Gibson sends an NSFW text to Greg.
The race continues for Greg Davies's golden head trophy. An interesting selection of facial hair and a fascinating collection of continuous noises.
Paul Sinha has some struggles with a basketball, Joe Thomas has a disastrous birthday and Sian Gibson will try to rescue Little Alex Horne from the sharp beak of an aquatic bird.
