A Certain Magical Index, Vol. 21 (light novel)

A certain unlikely hero...As battles rage around the world, three boys continue to dash through the fires of Russia. Takitsubo is still suffering, and with no cure in sight, Hamazura relies on a chance encounter and a borrowed jeep to find what he needs in Elizalinan territory. Already there is Accelerator, who awoke in a field hospital after his defeat at the hands of his weakest and most worthy opponent. Though Last Order is no better than before she and Accelerator arrived, it might be just the right place to learn how the occult parchment ties into everything. Back across the border in war-torn Russia, Kamijou is about to infiltrate another military base to finally corner Fiamma. That's easier said than done, though, when two enormous angels turn the entire area into a battlefield!