Saitama was enjoying a pleasant dreamworld fantasy about monsters strong enough to actually give him a challenge when suddenly he ends up on a completely different planet. In an alternate reality? And why is it raining so hard? Also, what do those sirens mean? Or, Saitama ends up on Earth Bet just before the canon Leviathan fight and things get interesting from there. Oneshot.

A world of Heroes and Villains come under attack from enemies beyond the stars! With the world's greatest hero missing, there's no telling how this invasion will end.

Some said there were places out there where you couldn't possibly have too much power. Some said Earth Bet was one of these places. Some were wrong. They were very, very wrong.

Brockton Bay receives a visit from the widely acclaimed strongest man on earth. Nothing will ever be the same.

Worm is a story containing Powers! It gets worse! Bullies! SuperVillains! It gets worse! Monsters! Warlords! Politics! Evil Conspiracies! It gets even worse! The End of the World! And Everyone Doing the Wrong Things for Right Reasons! ... Gah, that sucks. Let's add a little something more. Something called… … You thought I was going to say 'Heroism', right?