In this collection of poems that's a science, poetry, and adventure story all rolled into one, noted children's poet Jane Yolen takes readers on an expedition underground. This thought-provoking collection will evoke a sense of wonder and awe in readers, as they discover the mysterious world underneath us. Kids will explore everything from animal burrows, to human creations — like subways — to ancient cities and fossils.  Even deeper down, there are caves, magma, and Earth's tectonic plates. The illustrations show how girl and boy, accompanied by several animals, go on a fantastic underground journey. In these poems, young readers will see that beneath us are the past, the present, and the future.