In one of the most exciting scenes in 2008’s “The Dark Knight,” Batman infiltrated a secure building, captured a criminal that had fled the United States, and made his escape by deploying a balloon tethered to him that was snatched out to mid-air by a passing aircraft. The whole scene seemed like classic super-hero fodder — after all, there’s no way a human being could actually escape that way, right?

Think again. That scene was actually based directly on a very real CIA program called Skyhook (also known as the Fulton surface-to-air recovery system) — which aimed to help rescue downed pilots or spies from behind enemy lines without ever having to make a stop. The concept was simple (and not all that different from its depiction in “The Dark Knight”), with the downed pilot or fleeing spy deploying a balloon to around 500 feet, strapping themselves in, and waiting for a passing B-17 (or other aircraft) to grab their line and yank them out of harm’s way.

(CIA)

In order to accomplish this feat safely, pilots had to catch the line beneath the balloon and immediately pull up, otherwise the passenger on the other end of the line would find themselves dragged along the ground at 130 miles per hour — which is notably not all that safe a way to escape. According to estimates, Skyhook passengers would experience 7 Gs as they were snatched up off the ground, which while uncomfortable, is highly survivable (as demonstrated with both humans and sheep in the below video).

Once airborne, the crew aboard the aircraft would winch the person up in a matter of minutes, saving them from having to make the rest of the ride dangling hundreds of feet below.

(CIA)

This crazy concept actually saw operational use in the 1960s, starting with the extraction of a CIA officer from an abandoned Soviet Ice Station in May of 1962. Of course, there’s not a lot of information regarding other times the Skyhook methodology was employed because of the clandestine nature of the CIA’s work, but it seems feasible that variations on this theme could continue to be employed in some circumstances today.

Check out the real Skyhook in action below: