What it’s like to be a first responder amid the rise of synthetic marijuana.

Inside the DIY world of synthetic drugs.

Perpetually reinvented through experimental chemistry, manufactured in Asian mills, packaged in foil with names like White Slut Concentrated and Charley Sheene for use as “hookah cleaner,” distributed in college town head shops, snorted and injected by hardened addicts and high school thrill seekers alike, bath salts may be the strangest and most volatile American drug craze since crack. And they’re (quasi) legal.

How synthetic drugs became a booming (and mostly legal) business.