This is a fast paced, engaging series that encourages mind power and problem solving. Each episode sees two teams building two vehicles in an engineering and building challenge that will push them to their limits. They battle it out to win £5,000 which is secured in a safe. To win the money all the teams need to do is open the safe ? the only problem is the safe?s location is somewhere seemingly inaccessible. The teams have two days to build a vehicle which will enable them to reach the safe. On the third day the teams race to the safe, picking up numbers for the combination to the safe along the way. The first team to complete the course gets to use the numbers collected to attempt to break the safe?s code. Machines include an amphibious vehicle, an earth mover, a fire engine and a tank.