Chris and Xand van Tulleken bring a group of children under the age of seven to London's Covent Garden to complete a series of temptation tests. Elsewhere, the pair set out to explore how we develop a sense of right and wrong and what makes one child well behaved and another naughty. Meanwhile, five-year-old Yorkshire farming cousins Kieron and Rita tussle over some abandoned money, and seven-year-old Alfie and twins Taiya and Tyiana agonise over what to do when they are left alone in a sweet shop.