The chemists at the wonderful YouTube channel, Periodic Videos, explain what the deadly nerve agent VX is and why it is so good at making people drop dead. As you might recall, VX is the stuff used to assassinate the half-brother of North Korean dictator Kim Jong-un at a Kuala Lumpur airport.
From what I learned here, when VX comes in contact with your nervous system it won’t allow your muscles to relax. It causes convulsions and asphyxiation.
Here’s an extra video: