What was supposed to be a jolly 'Running Man' Christmas special quickly went south when the cast discovered that Gary was missing!

In order to win, the rest of the cast - divided into pairs - would have to find Gary and stand with him inside an octagon, which would only open at 9 PM that evening.

With the only evidence being his cell phone, they found a suspicious phone call which led to a very surprised Gil, the other half of Leessang. Caught unawares in a tracksuit outside his home, he was promptly dragged into the investigation.

A mysterious package delivered to Gil contained other juicy tidbits: a photo of Dynamic Duo, Gil, Jo Jung Chi and Jung In, as well as a photo of girl group A Pink.

Upon careful investigation of these leads, the cast members found out that the whole schtick was none other than a carefully planned out act by Leessang! Gil and Gary had collaborated to put one over the rest of the 'Running Man' cast members.

For Leessang to win, they had to hide the ruse from everyone and stand together inside the octagon. Although the rest of the cast were now aware of Gil's implication, they still didn't know that Gary's incarceration was fake, which still gave them a hidden card left to play.

However, when Yoo Jae Suk discovered Gary hiding in a corner far away from his purported jail room, Leessang's chances looked bleak. With the Blue Team escorting Gary to the final location to stand inside the octagon with him and everyone else hold a suspicious Gil hostage, everyone clashed outside the octagon to fight over Gary.

Taking the chance, Gil sneakily slipped inside the octagon with Gary, they turned things around by snatching victory from the sure jaws of defeat!

Winning the 'Running Man' Christmas episode three years in a row, Gary cemented his reputation as one of the toughest members to beat. Check out the full episode below!

SEE ALSO: 'Knowing Brothers' reveals teaser for next week's episode featuring Apink