In an era when many adventurers look to other worlds for discovery, Hunt (visiting scholar, Inst. for Public Knowledge, New York Univ.) goes in the opposite direction, burrowing into the shafts and tunnels leading into the earth. The author leads readers into abandoned train tunnels, Parisian sewers, old mines, and Australian ochre shafts. Hunt succeeds on a number of levels: daringly investigating the bowels of big city sewer lines, as an anthropologist among various cultures and archaeologist exploring long-forgotten ruins. Along the way, readers gain an appreciation of places and peoples seldom discussed, including the residents of sewers and other "intraterrestrial" voyagers. There's also a deeper layer to this work, such as discussions of origin stories, including Native American and Aboriginal Australian perspectives. Hunt is a pleasure to read; each page—like the subject matter at hand—offers a different and unexpected turn.