Welcome back to our 30 for 30 documentary short series.

In 1989, the storied Dallas Cowboys were a team stuck in mediocrity. They had a brand-new owner in Jerry Jones. They had a brand-new coach (just two years removed a national championship with Miami) in Jimmy Johnson. What they didn’t have was talent. But Dallas did have one asset that stood out: running back Herschel Walker. So Johnson went out to see what he could get for no. 34. Enter the Minnesota Vikings — a team that appeared to be on the cusp of many long playoff runs. All they needed was someone like Walker to put them over the top. They got Walker, but what did they give up? This film breaks down that deal and how the Cowboys’ new front office was able to give away one player and gain a dynasty of its own.

More on The Great Trade Robbery

• Director’s statement: Stuart Zicherman

Recent 30 for 30 Shorts

• Fields of Fear, directed by Alex Gibney »

• Kid Danny, directed by Andrew Cohn »

• The High Five, directed by Michael Jacobs »

• Mecca: The Floor That Made Milwaukee Famous, directed by Chris James Thompson »

• Posterized, directed by Andrew Jenks »