'This is Spinal Tap' never gets old. Fall Out Boy proved that last night (April 17) while performing their "comeback" hit 'My Songs Know What You Did in the Dark' on 'Conan.'

In the video above, bassist Pete Wentz gets trapped in his space pod for the opening of the song, suffering the same fate that befell the Tap's Derek Smalls. Luckily for FOB, Harry Shearer, who played the heavily mustachioed Smalls in the mockumentary, was onsite to help out and play the bass while Wentz was, um, predisposed. Guitarist Joe Trohman had no issues escaping his pod, however.

The band paid homage to another 'This is Spinal Tap' moment -- 'Stonehenge' -- later in the performance. It was quite a production and a recreation, but fun nonetheless.