The first thing your eye does is follow the bolt. A jagged stripe of scarlet and electric blue cuts diagonally from forehead to cheek across David Bowie's face, slicing him into halves. Below it his eyes are closed and rimmed in soft pink, lashes resting, lips parted slightly. His skin has been drained to a luminous near-white, his bare shoulders melting into a blank background, and just beneath the throat sits one small, glistening pool of liquid on his clavicle.

Above his head, in dripping red-into-blue letters, his name. Below, the title: Aladdin Sane, a pun that reads aloud as "A Lad Insane."

This is the face Bowie wore only once, and never again. It became the single most recognizable image of his career, a star and a sleeping mannequin at the same time. How that stripe got onto his skin, and why the whole serene, painted portrait still snags the eye more than fifty years on, is a story of one instruction, one photographer, and a piece of rock-and-roll jewelry.