Kim Jong-un's brother was assassinated with one of the deadliest chemical weapons ever created
It's almost like something out of a spy novel.
On Friday, Malaysian authorities announced that VX, the "deadliest nerve agent ever created", was used to assassinate Kim Jong-nam, the half-brother of North Korea's current leader, Kim Jong-un.
The alleged killers are believed to have wiped a substance on Kim's face at the Kuala Lumpur International Airport. The poison was so fast-acting that Kim died soon after, on the way to the hospital.
What is VX?
VX has been described as the "most potent of all nerve agents", and is so lethal its only known use is in chemical warfare.
Nerve agents are the most toxic and rapidly acting of all the known chemical warfare agents.
VX has been banned under the UN Chemical Weapons Convention, which North Korea has not signed.
This odourless and tasteless liquid was first developed in the U.K. in the 1950s.
It has an oily texture and is amber in colour.
How does it work?
Even a tiny drop of VX on the skin -- unless washed off immediately, could prove lethal.
Nerve agents work by preventing the operation of an enzyme that acts as the body's "off-switch" for glands and muscles.
Without this "off-switch", the glands and muscles cannot turn off, causing uncontrollable muscle contractions which eventually stop the victim from breathing.
Of all the known nerve agents, VX is the slowest to evaporate -- making its effects able to last over a long period of time.
Under average weather conditions, it can last for days on objects.
What happens to you if you're poisoned?
According to the Centers of Disease Control and Prevention, exposure to a low or moderate dosage of VX might include symptoms such as chest tightness, confusion, nausea and blurred vision.
Exposure to a large dose of the agent may result in convulsions, loss of consciousness, paralysis and respiratory failure leading to death.
Those exposed to a low or moderate dosage usually recover, though severely exposed people are unlikely to survive.
We wonder how well protected the assassins were, given that they came so close in contact with VX, but there's a chance they weren't aware of how toxic it was.
Hopefully they were carrying antidotes. You have to administer it almost immediately in case of contact, because the agent is so fast-acting.
Do any countries have VX?
North Korea is believed to possess between 2,500 and 5,000 tonnes of chemical warfare agents.
VX is ten times more lethal than Sarin.
VX and Sarin, another highly toxic nerve agent, is thought to be the focus of North Korean production.
The U.S. and Russia once had large stockpiles of VX.
However, the U.S. has destroyed its stockpile under the Chemical Weapons Convention of 1997, with the elimination completed in 2009. Russia has also worked to eliminate its supply.
VX is ten times more lethal than Sarin, which prior to this attack, was the focus of widespread media coverage 1995, after an attack on a Japan subway by a doomsday cult.
Syria is also believed to maintain a stockpile of VX.
UPDATE: Feb. 24, 2017, 11:08 a.m. EST Editor's Note: This story has been corrected to indicate that the U.S. eliminated its VX stockpile in 2009. An earlier version of the story mistakenly stated that only 9 percent of the VX stockpile had been eliminated.
Yvette is a Viral Content Reporter at Mashable Asia. She was previously reporting for BBC's Singapore bureau and Channel NewsAsia.
