Also known as: The Little Days Targeted Elimination Plan.
One is a clone of Accelerator, one of the few mutants among Accelerator's clones. His ability is vector control, and he works as a cleaner for Academy City's Dark Side, the kind who handles cleanup and silences witnesses.
Then one day, an anomaly appears among Accelerator's brothers, bringing memories from another world.
Accelerator doesn't think those memories are fake. He wants to see that world for himself.
So he uses his ability.
The good news is that he's escaped the Academy School Life plane.
The bad news is that this world seems even worse than Academy City.