Among the many beautiful, unexpected and sometimes revolutionary discoveries to emerge from subatomic physics, probably none is more bizarre than an elementary particle known as the "neutrino". More than a trillion of these microscopic phantoms pass unnoticed through our bodies every second, and indeed, through the entire Earth - but their properties remain poorly understood. In recent years, exquisitely sensitive experiments, often conducted deep below ground, have brought neutrino physics to the forefront. In this talk, we will explore the neutrino - what we know, what we want to know, and how one experiment in a New Mexico mine is trying to get there.