The visuals from the Willy Wonka pop-up attraction in the UK are pretty sad and underwhelming ... but the script is even worse, and more out of touch with reality.

The 13-page script that the actors were given to perform at the now-viral "Willy's Chocolate Experience" in Glasgow, Scotland, has surfaced online ... and if you thought the actual experience itself looked rough, wait until you get a load of the fake plotline behind it.

The first thing that jumps off the page ... set descriptions painting a picture of a whimsical, enchanting and immersive experience do not line up AT ALL with what was actually awaiting paying parents, who ended up demanding refunds for the bait and switch.

The trainwreck doesn't end there ... the script is littered with predictions for how the audience would respond to the set and the actors playing Willy Wonka and the Oompa Loompas ... but the rosy outlook didn't play out that way in real life.

Paul Connell, the actor hired to play Wonka, says the cast only got the script the day before the event, leaving them little time to memorize their lines ... and he told The Independent the writing was a bunch of AI-generated gibberish.

A perfect example of how the script greatly deviates from the real deal ... the "Bubble and Lemonade Room."

In the script, the space is described as "a room where the air sparkles with floating bubbles, and rivers of sparking lemonade flow freely." Sounds cool, but in reality, it's just a fold-out table with plastic cups containing a few sips of lemonade ... and a clearly visible trash bag.

There's also mention in here of some kind of evil villain/spirit thing called The Unknown -- and video of an actor portraying it during one of the tours last weekend is out too.