It was an Avengers fic with Tony busy inventing stuff. Also Loki may have been a part-time Avenger or something of the sort because he and Tony were working as a team.
What I remember best is that somehow Tony decided to "improve" roombas and kept on until he had made them so they could fly; he also wanted to buy the roomba company itself. I also remember that the Bad Guy was a dust cloud (?) ended up getting eaten by the flying roombas, which totally freaked the entire team out. Fury told Tony that the incident of the flying roombas put Tony in the Evil Overlord category.
Also, I think something *very nasty* happened to Dr. Doom and some of his higher-up officials. Maybe they were turned into pigs?