Certain Magical Index, Vol. 19 (light novel)

A certain unlikely hero...In the shadowy underbelly of Academy City, the problem-busting team known as Group (centered around Level Five esper Accelerator and the man who wields the powers of science and magic, Tsuchimikado) is investigating every lead they can related to the word dragon. This clue may be the key to finding their way out of a terrible situation. Unfortunately, their efforts put them at odds with a particular member of the General Board, the highest body of authority in Academy City. Once again, Group finds itself in the center of a gunfire-filled conspiracy...just as former Item member Hamazura stumbles onto the scene?!