In the Arizona desert, Buddhists will embark on a three-year silent retreat

There will be no word from the outside world in the Great Retreat, only the quiet of rock and cactus. Adherents hope to find enlightenment in the silence, a gift they plan to share when they emerge.

Deep in a remote desert valley, where rattlesnakes lurk in the scrub, Stéphane Dreyfus and several dozen other Buddhists are preparing to undergo a mind-altering journey: