Remember the opening credits to 'Malcolm in the Middle'? There has always been a mystery about where one of the clips originally came from.

Spanning seven seasons and 151 episodes, 'Malcolm in the Middle' was comedy gold when it was first released by FOX in 2000. All of these years later, we're still fans (and we're eagerly awaiting for it to arrive on Disney+ at some point in the future).

Starring Frankie Muniz as the awkwardly smart Malcolm, his fiery mother Lois played by Jane Kaczmarek, and an easy-going Hal brought to life by Bryan Cranston, the series also featured one of the most memorable opening credits from that era.

The theme song set to 'Boss of Me' by alt-rock band They Might Be Giants featured early moments from the TV show mixed with various movie and TV show scenes which were distorted and cut together. The 11 non-'Malcolm' video clips featured moments from the likes of 'Clash of the Titans', 'The Brain from Planet Arous', and a Bret Hart and Chris Benoit wrestling match.

However, there was one clip - the one of a ski jumper on fire - that has remained a mystery for these past 21 years. It's been a burning (sorry) question on the internet for many years as fans and internet sleuths attempt to track down the original source.

And so, one YouTuber - Kid Leaves Stoop - took on the challenge of tracking down this video clip. Fans already suggested that the clip was from a reality TV series from the '70s named 'Thrill Seekers' - however, the actual clip used in the show is different to the one used in 'Malcolm in the Middle'.

But, was it really a 'Thrill Seekers' clip? Here's the full investigation, which is worth all seven minutes of your time.