Once again, the hermit kingdom has popped its head out onto the international stage. And once again, it’s for all the wrong reasons. 

You’ve probably read in the news something about the assassination of Kim Jong-nam, the half-brother of North Korean supreme leader Kim Jong-un. Just today, the lead antagonist in this bizarre political drama has been revealed: The VX nerve agent.

Malaysian police say that his assassins wiped Jong-nam's face with the agent in Kuala Lumpur airport, amid suspicions this defected playboy had come too much of a liability to his half-brother. North Korea, of course, denies any involvement.

Here's everything you need to know about this fascinating and deadly chemical.

What Is VX?

The VX nerve agent, also known as ethyl N-2-Diisopropylaminoethyl Methylphosphonothiolate, is about as fun as its sounds.

This highly toxic chemical is one of the most potent and deadly of all known chemical warfare agents. It’s around 100 times more potent than sarin, another terrifying agent used in chemical warfare and terrorist attacks such as the 1995 Tokyo Subway Attack. Just one drop, or about 10 milligrams, of VX on bare skin can be fatal, according to the Centers for Disease Control and Prevention.

Its physical appearance appears fairly innocent, coming in the form of a clear, tasteless, odorless, amber-colored, oily liquid.  

What Does VX Do To The Body?

VX is notoriously fast-acting. Within minutes the person will experience pinpoint pupils, runny nose, tightening airways, fluid build up in the lungs, and difficulty breathing. If the dose is high enough (which is still a relatively tiny amount) you will go on to lose consciousness, have seizures, convulsions, muscle twitching, paralysis, and eventually death by suffocation.

Nerve agents in general work by shutting down the nervous system. In a nutshell, the agent binds to the active site of the acetylcholinesterase, the enzyme that catalyzes the breakdown of acetylcholine. Acetylcholine is a neurotransmitter associated with muscle contraction. If it’s unable to break down, it keeps “refiring” and prevents the muscles relaxing. Understandably, this is not good news for any part of the body.

Where Did VX Come From?

Like many of these nerve agents, VX started life as a pesticide. Although it was developed by a chemist in the UK, the US military quickly became aware of its much bigger and more sinister potential.

Only the US and Russia have ever admitted to possessing VX. However, other countries and organizations are suspected of owning stockpiles, including the Syrian government. The Nuclear Threat Initiative claims that North Korea owns up to 5,000 tons of chemical weapons, with “Sarin and VX thought to be the focus” of their production.

While it’s unclear how this chapter – or, indeed, the whole North Korea saga – will play out, one thing is for certain: Don't play around with VX.