It's the drug that appears to leave users frozen in time, with little or no awareness of the world around him. And, in some cases, it can be deadly.
Spice is Britain's latest drug craze, smoked like marijuana but far more potent - so potent, in fact, that it appears to leave people in a zombie-like stasis.
But where exactly has this new drug come from, and why exactly does it have such a crippling effect on those who consume it?
Well it was actually invented by a scientist called John Huffman, who was examining the effects of cannabis on the brain. He created a far more potent synthetic version of weed, but soon realised just how dangerous it was and labelled it unfit for human consumption.
However, in a chain of events reminiscent of a low-grade horror flick, the sinister new drug was smuggled out of the lab and ended up infecting regular people, who were looking for something different to inhale and didn't realise the consequences.
Just like marijuana, Spice is made of cannabinoids. In fact it's so similar to the drug that inspired it that some people have taken to calling it 'fake weed'.
Yet the effects of Spice can be far more severe than regular weed. We're talking severe psychotic episodes, hallucinations, vomiting, seizures and withdrawal symptoms worse than those left by heroin or crack cocaine.
The reason for this startling difference is that unlike regular marijuana, the cannabinoids are synthetic, and there are lots of different ones - so the potential combinations are myriad. Some synthetic cannabinoids are 100 times stronger than THC, the active ingredient in marijuana, and one of the chemicals used in the early days of Spice has now been labelled a toxic poison.
To make things even more confusing, and dangerous, each manufacturer will have their own 'recipe' and will lace the cannabinoids with all manner of products, from alcohol to hydrochloric acid and even bug spray. The cocktails can be truly frightening, even by the standards of illegal drug-makers.
Yet vendors will often try and convince people that Spice is natural and harmless, and this has helped fuel its propagation in both Britain and America - with thousands of people attracted by its low cost, dramatic effects and harmless pretense.
The drug has spread particularly rapidly among the homeless population; in fact youth charity Lifeshare has estimated that about 95% of young people who are homeless use the drug, The Sun reported.
Police have warned of the "chaos" caused by the drug, and news stories about its devastating effects have proliferated in both Britain and America. A range of drug charities have created dedicated pages for the substance, offering advice on its composition and effects.
Yet for the movement it seems this horrific zombie tale still has plenty of legs, and we're a long way from seeing the Spice genie put back in the bottle.