Dark Horse.(Daniel Radcliffe)

Byline: Photographed by Annie Leibovitz.

Daniel Radcliffe's stage debut in Equus, writes Adam Green, marks the arrival of a serious, mature talent.

Like cartons of milk, most child stars carry a "sell by" date, generally coinciding with the onset of puberty, after which they start to curdle. There have been notable exceptions, of course--Jodie Foster comes to mind, and Christian Bale--but by and large, once kids who have grown up in the public eye stop being adorable, they find themselves trapped by the image of who they once were and tend to self-destruct or fade away.

Which is what makes the metamorphosis of Daniel Radcliffe, otherwise known ...