A Certain Magical Index, Vol. 32 (manga)

Deep in the shadows of Academy City, Accelerator has gathered with the rest of Group for a new mission. An armed terrorist group has holed up with a bunch of kids as hostages and it's up to the number one esper to save the day and dispose of the evidence. But while playing hero is all well and good, more important to Group is what the terrorists are after-one of the city's most guarded secrets, known only as "Dragon"...