-[Henry] Now, I'm sure you've heard of the infamous Western Front.

-Yeah, yeah.

-But did you realize that your grandfather had served there?

-No, I had no idea.

-How would you have fared?

How would you have processed that experience?

-Yeah...no.

-[Henry] No?

-We were spared that.

-Yeah.

-[Brian] We've been spared that.

-I would have been crushed.

-Yeah, I mean, it's beyond imagination.

-[Henry] Mm.

Could you please turn the page?

-[Brian] Sure.

-[Henry] Brian, these are excerpts from the war diary of the 9th Battalion of the Black Watch from late 1915 and early 1916.

Now, we believe that your grandfather was in that battalion at the time.

Would you please read the transcribed section?

-"December 11th: battalion went into the trenches.

The trenches were full of water, two feet deep in places.

February the 20th, between nine and 10PM: heavy artillery firing was heard to the south.

March 18th: we were heavily shelled at 11AM and again from 5:30 to 7PM.

Gas from the shells was distinctly noticed."

Yeah, wow.

-[Henry] And we believe your grandfather was there.

-Yeah.

-[Henry] What's it like to read those words?

To think of your grandfather actually living through that, experiencing that horror?

-I think that explains a lot.

It's not a fantasy.

It's a reality.

And he lived with that harsh reality.

-Mm-hm.

-You know, I mean, apparently, he was a drunk, he drank, and I think it all makes sense; it just makes sense.

And he-- I mean, he didn't live very long; he died at the age of 50.

-Mm-hm.

-[Brian] So he didn't live long, you know.

And it doesn't excuse anything, but it fills in a lot about... what he was going through and what he went through, and how he didn't deal with it, how he couldn't cope with it.

-[Henry VO] Very few men could cope with what James endured.

He and his fellow soldiers were subjected to near-constant bombardment.

[explosions and gunfire] And some of the shells contained poison gas.

It would settle in the trenches.

Men who breathed too much would find their lungs blistered and burned... if they survived at all.

It was one of the most gruesome weapons ever seen on a battlefield, and James may have been one of its victims.

Five months after he arrived in France, he found himself in Harley Hill Hospital in Yorkshire, England.

-[Brian] "James McCann, Sergeant, age 39... cough, short of breath.

Four days, no duty."

-[Henry] Your grandfather was admitted to the hospital for issues related to his lungs.

Did you ever hear anything about that?

-No!

Wow.

No, this is all new.

-[Henry] His diagnosis was that he was short of breath and he was coughing, so let's see why.

Could you please turn the page?

Brian, this is your grandfather's pension card, issued to him after the war.

Would you please read the transcribed section?

-"Cough and dyspnea, chronic bronchitis and emphysema.

Degree of disablement: 30 percent."

-[Henry] So you know what this means?

We spoke to a scholar, who told us that your grandfather's symptoms were typical of gas poisoning.

-[Brian] Wow.

-[Henry] What's it like to learn this?

-It...

It's relieving, actually, because it's like a ghost is being laid finally, you know.

-[Henry] Ah, good.

-You know, that hadn't been laid; you know, that had been so, um... debatable.

And especially that he had a particularly bad rap.

You know, he was a drunk, he wasn't, you know... And nobody's taken into account any of this.

-Yeah, it wasn't his fault.

-[Brian] No.

-Yeah.

-No, I mean, and it's how he survived.

-[Henry] Mm-hm.

-Oh, boy.