The Hidden Treasure Of Area Zero DLC for Pokemon Scarlet & Violet comes in two parts. Not only are these DLCs connected stories, but they also provide story ties to the main game. This is most obvious just after the ending of The Indigo Disk, as there's a secret cutscene that's just as easy to trigger as it is to miss.
Pokemon Scarlet & Violet DLC: The Indigo Disk Secret Ending, Explained
There's a lot of surprises within the secret cutscene after the end of The Hidden Treasure Of Area Zero in Pokemon Scarlet & Violet's DLC.