With only four teams left in the competition, tensions are running high. In this round, teamwork is crucial for any chance of earning a place in the semi-final.Steely determination and concentration is the order of the day as teams use every tactic possible to gain an advantage in the Catapult Chaos challenge. This is the one with points up for grabs, but hitting the target isn't as easy as it looks. It's make or break once those turnips are unleashed.With some points to be redeemed, the next challenge, How's She Cuttin', relies on artistic flair and accurate mowing skills. It's all a bit of a pig's mess, even for our most talented tractor artists - have they enough points to stay clear of the ultimate tractor-off?In a thrilling finale, the Bog Run race decides who's staying and who's going home. This is a fight to the finish. Once the wheels stop spinning and mud stops flying, who will screech their way into the semi-final?