You're listening to the inquiry on the BBC World Service with me,

Helena Merriman.

Each week we bring you four expert witnesses,

answering one pressing question from the news. The first thing you notice is a tightness in your

chest, a shortness of breath. You feel dizzy, confused, and your skin starts to sweat. You don't know it

yet, but your nervous system is under attack and your muscles are shutting down. You start to drool and vomit. Your lungs fill with liquid and your heart starts to spasm.

This is what happens to your body after it comes into contact with a nerve agent.

It's what happened to the former Russian spy Sergei Scrippel and his daughter in Britain in March this year. It's what's suspected to have

killed over 40 people, mostly women and children in Syria a few weeks ago.

Yet these nerve agents were banned over 20 years ago. Hundreds of countries supposedly

destroyed their entire stockpiles. So where had these nerve agents come from?

This week we speak to four of the world's most experienced chemists and researchers as we ask our nerve agents out of control.

Part one, colorless and odorless.

I was a month before my 19th birthday, a babe in arms and I remember to this day walking through

the gates of the Royal Military Academy at Sandhurst.

Our first expert witness, ex-army Intelligence Officer Philip Ingram.

He spent 26 years working for the British military, much of it during the Cold War, a time

when soldiers on both sides trained for a new kind of warfare.

You get issued your chemical protection kit, It goes with you everywhere at all times and in there we had a drug called atropane and atropane is one of the

antidotes for nerve agents.

Philip Ingram knew more about these chemicals than most. He'd studied what some call the chemistry of death at Britain's Royal Military College of Science.

There, he'd learned about the so-called father of nerve

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