When we think of 9/11 in the USA, everyone naturally thinks first and foremost of the terrorist attacks surrounding the plane hijackings and the collapsing Twin Towers, which traumatised an entire society. However, another attack that took place just a week later in the USA has been somewhat forgotten. This time the murder weapon was much less spectacular, but no less perfidious. It was very simple envelopes that caused or were intended to cause death. They contained anthrax spores, alternatively known as anthrax.