have you ever wondered what happens underground? or asked questions such as, what do people hide in their cellars? where does poo go when we flush the toilet? and where does all of our rubbish get hidden? well... 'let's take a journey deep down below, where lots of things happen that you may not know. we'll peel back the pavement and jump right on in, so come on, get ready, we're about to begin!' what happens underground? is an informative and fun, illustrated book for children of all ages who have ever wondered what goes on beneath their feet.