Cryptic symbol will appear around Atlanta with no explanation.
Each Mellow Mushroom location will also showcase the cryptic symbol.
In-store TVs will glitch to this mysterious message.
Inspired by a spaceship and a mushroom colliding, the pop-up will have a brewery side and a pizza side.
On launch day, the Beer From Beyond will be available at all Mellow Mushroom locations, as well as the pop-up - in Piedmont Park in Atlanta.
People will be hired to act like loony conspiracy theorists and will usher people towards the pop-up.