No mystery here...it just sold out really, really quickly.

Airbnb and Warner Brothers offered an overnight stay in the "Mystery Machine" from the "Scooby-Doo" live-action film, and it sold out within minutes!

The idea was to celebrate the 20-year anniversary of the movie's release.

The iconic van will be parked on the Malibu coast in southern California for three one-night stays starting Friday.

The lucky guests who got the stay for $20 for the night acted fast...and will get to re-watch the movie in the van, while enjoying lots of "Scooby snacks,” such as hot dogs and eggplant burgers.