Little bros Wisdom and Callum task their big bros, Kenny and Adam, to prove who is the biggest bro in a series of madcap challenges! The winner will be revered as top bro, while the loser takes a spin on the forfeit wheel of doom! Waking up to find enormous cranes on their doorsteps, Kenny and Adam are set the challenge of protecting three valuable items from two HUGE drops. Which bro has the skill to save a slime balloon, foresight to fortify their phone, and the vigilance to avert outright vandalism to their mum's favourite vase? And if they can survive the biggest drop, can they prove themselves further by building the biggest hat!? Big challenges indeed - the winner will stand tall, and the loser... will have to eat an entire, extremely sour, lemon!