Adult Swim’s Rick and Morty is so popular that it regularly spawns memes that take over the internet, but the show’s fandom has spilled over into real life as the result of a throwaway line about a 19-year-old condiment.

In 1998, as a promotional tie-in for the Disney animated film Mulan, McDonald’s expanded its line of Chicken McNugget dipping options with “Szechuan sauce.” (The film takes place in China during the Han dynasty.) The fast-food chain soon retired the sauce, and seemingly everyone forgot it existed — except for the writers of Rick and Morty, who included an offhand joke about Rick searching for Szechuan sauce in the premiere of the show’s third season.

McDonald’s later drew the ire of a portion of Rick and Morty’s incredibly passionate fanbase when it revived Szechuan sauce for a one-day promotion last week — but only in limited quantities at certain locations. Fans who missed out on the pop-culture phenomenon turned on McDonald’s employees, and the company quickly apologized and pledged to bring back the sauce for everyone this winter.

You can follow all the developments of the Szechuan sauce fiasco in our StoryStream below.