Backgroundcharacterdeath Stories

REMINDER: This story is NOT MINE! The original is by Sum_Lu_Zer on AO3. Please go show some support to him It has been several weeks since Meggy and Mario's relationship was made known to their friend group. Although most of them approved of it, not everyone took the news so well, especially a certain mushroom man...

Lacy and her friends have to save the world, which is kind of being destroyed by radiation. And the fact that half of it is missing. Can they save the world? Sci-fi type 'end of the world' story, with some slight fantasy vibes at the end. Also as stated in the tags, there is a background character death.