This week, The Forum delves into the subterranean world of life underground – from the forgotten tunnels and catacombs of our cities to life found in the stifling sunless world two miles below the Earth’s surface. Might humans one day retreat underground if living above ground becomes too tough? Bridget Kendall with Social Geographer Dr. Bradley L. Garrett, Zoologist Dr. Gaetan Borgonie and Isotope Geochemist Professor Barbara Sherwood Lollar. Photo: Car Quarry image (credit: Bradley L. Garrett)