Max and Maddy are on the trail of a criminal who`ll stop at nothing to sabotage Mr Helium`s trans-American hot-air balloon race. The prize is a gold balloon worth one million and one dollars, and all the money raised by the race is to go towards the Home for Children Whose Parents Have Disappeared in Balloons - so there`s a lot at stake! They take to the skies on board Mr Helium`s very own balloon in order to catch the cheat. But will the detectives become victim to the dastardly villain`s dangerous schemes and dirty tricks, or will they blow his plot sky-high?