Who Planned the Assassination of Kim Jong-un’s Half Brother?

It’s the stuff of spy novels: On February 13, Kim Jong-un’s estranged half brother, Kim Jong-nam, was ambushed in a Malaysian airport by two women bearing VX nerve agent — a lethal chemical weapon 10 times more powerful than sarin. He died en route to the hospital.

The trial of the two alleged assailants, Siti Aisyah and Doan Thi Huong, began in a Malaysian court on Monday, with Aisyah and Huong facing the death penalty for their role in the murder. It’s a role they’ve claimed they were tricked into: They say they had been told they were carrying out a harmless prank for a hidden-camera YouTube show. They have both pleaded not guilty.

Who orchestrated the deadly attack on Kim Jong-un’s half brother — and what does it reveal about the North Korean leader and his regime?

That’s the question at the heart of a new FRONTLINE documentary, North Korea’s Deadly Dictator. Premiering on Wednesday, the documentary examines claims that Kim Jong-un and his intelligence services orchestrated the hit — and explores what the assassination reveals about the North Korean leader’s intentions and capabilities.

“If you want to understand what’s actually going on in Pyongyang … one of the things you have to understand are these rare moments when the palace opens its doors inadvertently and lets you in,” Evan Osnos of The New Yorker says in the above scene from the film. “And one of those moments — perhaps its most spectacular moment — was the assassination of Kim Jong-nam.”

Drawing on interviews with a leading North Korean defector, diplomats, Kim Jong-nam’s school friends and even a former North Korean secret agent, North Korea’s Deadly Dictator sheds light on the inner workings of the Kim family, and how Kim Jong-un is trying to ensure his regime’s survival.

“I think Kim Jong wanted to make a point to any would-be rivals, potentially opponents, defectors out there, saying, ‘I can kill you in any manner.’ So, I think he wanted it to be public, he wanted the whole world to know,” Sue Mi Terry, a former CIA analyst, says in the film.

As tensions between President Donald Trump and the North Korean leader escalate, the documentary is a rare, inside look at one of the world’s most secretive regimes.

North Korea’s Deadly Dictator airs Wednesday, October 4 at 10 p.m. EST/9 p.m. CST on PBS stations (check local listings) and online.