Gibson is on the hunt for one very special guitar: The cherry red Gibson ES-345 used by Marty McFly to play Chuck Berry’s Johnny B Goode in the 1985 hit movie Back to the Future. Remember it? Course you do.

To mark the movie’s 40th anniversary, the legendary guitar maker has decided it wants to track down the whereabouts of the iconic instrument, and it’s even called on those connected to the movie to help it in its quest.

In a star-filled video (top) released on Tuesday, Back to the Future lead Michael J. Fox says: “We need your help. We’re trying to find the guitar I played in Back of the Future. It’s somewhere lost in the space-time continuum … or it’s in some Teamster’s garage.”

The actor adds: “ If you know where it is, if you know who has it, call us, text us.”

Christopher Lloyd, who played the mad scientist Dr. Emmett Brown in the movie, also chimes in, saying: “Somehow, it’s vanished … This guitar has been lost to the future.”

Ah, lost to the future, that’s catchy. Well, it turns out that the search for the Gibson ES-345 will form the basis of a documentary called just that: Lost to the Future. The project appears designed to engage fans of both the movie and the guitar, while also documenting the guitar’s impact and its mysterious disappearance.

On the YouTube page featuring Fox et al, Gibson elaborates: “When it comes to guitars in movies, no guitar was more iconic or more influential than the cherry red Gibson ES-345 used by Marty McFly to play Johnny B Goode in the movie Back to the Future. That scene has been cited by countless artists as the moment they knew they wanted to play guitar.”

It adds: “One problem: the guitar has been missing since 1985, and no one knows its whereabouts.”

The documentary team will apparently “search the globe” for what Gibson insists is “the most important guitar in cinema history.” Guess Spinal Tap‘s “never played” guitar doesn’t quite cut it.

So, Back to the Future‘s Gibson ES-345. Do you know where it is?