In a cluttered living room in south London, Lee Hogan, a sound engineer and part-time disc jockey, perches on the edge of a cheap leather armchair and bends his head towards a glass water pipe. A friend, kneeling on the floor, holds the stem of the pipe and uses a cigarette lighter to burn a tea-smelling herb. The herb glows red, and as it does so, Hogan places his mouth over the aperture of the pipe (better known as a 'bong' to those in the know). He breathes in deeply, taking a lung-full of smoke.
It's the way that many people choose to inhale marijuana, but this weed is far more potent and far more harmful. Hogan is smoking salvia divinorum, a species of sage that also happens to be the most powerful hallucinogenic herb known to man. It's also perfectly legal.
It doesn't take long for the effects to take hold. Seconds after breathing in the smoke, Hogan leans back in his chair and lets out a deep, slightly manic laugh. He hugs himself and starts to giggle. The giggle then transforms into a whimper, which, in turn, becomes a series of high-pitched squeaks. He is trying to talk, but makes no sense whatsoever. Then, mouth hanging wide open, he looks around the room. His eyes have glazed over and he doesn't seem to know where he is. As he slowly manoeuvres himself in his chair, his head rocking from side to side, he looks like a man who has just been hit over the skull by an iron bar.
Later he tells me that, by this stage, he had started to imagine he was a toy soldier carrying a rifle and dressed in a tall black hat, red coat, white trousers and black boots. His friends, known in salvia-speak as 'sitters' – present to make sure that the user does not harm himself or others – looked like enemies on his imaginary battlefield. After a minute, he falls out of his chair and shuffles along the floor on his knees. He clumsily removes his top – he is wearing a shiny hooded jacket with oversized earflaps and large sunglasses – and nearly sprawls across a table in the process, then sinks back into the chair, his head in his hands, his T-shirt pulled up to his chest, a rumpled, incoherent mess.