Humming in the kitchen of Bugg and Dilan's new home is a huge, mysterious fridge. Even when Bugg turns off the power, the light stays on. Plus, it's full of strange-looking yoghurts in glass jars with wax-paper lids. They bravely eat some and the yoghurts take them back to 1974! What follows is a desperate scramble across time and space, as the siblings try and right a 40-year-old time crime...