Silent meditation retreats have become so commonplace as to be nearly mainstream. Darkness retreats, though, are an entirely different sort of practice. In a sealed room in a cabin in the woods, a cabin owned by a onetime Riker’s Island chaplain, Chris Colin comes face to face with—well, with nothing. That’s what happens when light disappears for three days. It doesn’t mean you don’t see things, though.

A strange dam broke. Just minutes later, the tape along the bathroom door came loose, lighting up that side of the room. I shot up to cover the leak, only to discover I imagined it. I trekked to my cushion, and I was now inside a snow cave. The cave morphed into the Milky Way, so vivid that comets zipped by. Soon I was in an old stone fortress. (Habsburgian, I somehow knew.) Moonlight poured through a hole in the roof, bathing the floor in a pale blue and illuminating a column of dust. In normal life, I struggle to summon visuals in my head; here I was Rembrandt.

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