Webster's describes yoga as a system of exercises for attaining bodily or mental control and well-being. But to its most dedicated adherents, yoga is the key that unlocks the secrets of the universe. Passing through that door is best accomplished with the help of a guide. Finding one in Houston, where yoga is booming, is easy. The city boasts a number of respected master instructors, including George Purvis and John Friend. We direct novices to The Yoga Institute & Bookshop, where owner Rae Lynn Rath and manager Becky Jordan have a combined 54 years of yoga practice and study under their belts. Rath and Jordan are disciples of Friend, the founder of Anusara, one of the newest and fastest-growing schools of hatha yoga. Anusara means "flowing with grace," and it describes an approach that integrates the rigorous physical demands of yoga with emotional, mental and spiritual expression. Or as Friend puts it, "It is a willingness to be aware of all parts of ourselves: the light and the dark, the full rainbow of sensation, perception, emotion and thought." Confused? Then visit the Institute's bookshop, which offers a sizable collection of books and videos on Anusara and other yoga styles, as well as plenty of information on meditation, holistic medicine and other aura-sharpening practices.