A high-school-age girl attempts suicide, but finds herself at the mercy of a fanatical group calling themselves "DA." When a young woman carrying a photo of Last Order is pursued through the hospital, Accelerator determines to find out why.

Accelerator takes on the two DA members in the hospital morgue, and receives assistance from an unexpected source. When DA once again messes up a mission at the hospital, plans go into motion to have them removed from the operation.