On July 30, Britain's - Prince Harry arrived at Featherstone Lodge, a drug rehab center in a gritty south London neighborhood, without the usual royal pomp and circumstance. Instead, PEOPLE reports in its latest cover story -- about the revelation and aftereffects of Harry's pot and alcohol use -- the prince, then 16, slipped quietly into the red brick building for a tour by a recovering addict. "He asked several residents, 'How did you come to be in rehab?,' " Featherstone staffer Wilma Graham, who attended the meeting, told the magazine. "And I think he was quite shocked to hear that you can be using 'soft' drugs and that suddenly you're moving toward hard drugs. I think it was quite an eye-opener for Harry." And these were eyes that apparently needed opening, PEOPLE reveals. According to reports, Harry drank alcohol with pals at the Rattlebone Inn, a pub in Wiltshire near the family's Highgrove estate, and smoked dope in the Rattlebone's backyard shed; he also reportedly enjoyed "lock-ins," the common practice in which a pub owner locks the door at closing time but continues to serve drinks inside. Sometimes, too, PEOPLE quotes one newspaper account as reporting, should Harry spot a young English rose he'd like to know better, the young royal, third in line to the throne, would approach her at the Rattlebone with the line, "Do you want to come back to my palace for a drink?"