Something Is Haunting Riverdale High - S1.E19

Midge, Dilton, and Ethel aren't exactly the most popular of kids, so no one thinks much of it when they go missing. However, when Archie is rendered invisible and untouchable by one of Dilton's inventions he finds that he must work with them to stop the haywire machine from turning Riverdale into a ghost town! Can Archie learn enough about the classmates he usually ignores to help them turn the machine off, especially when they can barely move a stack of papers?