The screamer sounded off and everyone began to leave quickly. You have to leave quickly when you hear one of these things. They send out a mixed brew of devilish sounds at the decibel level of a major earthquake. Some are audible, sounds like a magnified fingernail on a blackboard, while others are supersonic and produce sensations of panic and imminent death. Harmless and highly effective. The street was otherwise empty when I walked out to the car that was just pulling up to the curb. My head was throbbing with the supersonics that got past the plugs and I was more than happy to slip through the open door and relax while Angelina gunned the machine down the street.