From the back cover:
With reports of powerful intruders defeating a number of assistant captains, the inner sanctum of the Soul Society—the Seireitei, the home of the Soul Reapers—is put on a state of high alert. Matters are further compounded by the mysterious death of a prominent captain. Is his death a cover-up to prevent a valuable secret from being exposed?
Meanwhile, Ichigo confronts Kenpachi Zaraki, captain of the eleventh company, and by far the most brutal fighter in the Seireitei!
This volume was similar in structure to the last: one of the secondary characters got to be a badass (Chad this time), Ichigo had a fight with an opponent more difficult than the last (a powerful Soul Reaper captain), there was a flashback chapter providing character backgrounds (how Chad and Ichigo met and became friends), and more members of the Soul Reaper guards were introduced.
While everything was sufficiently entertaining, the parts I liked best pertained to the Soul Reapers. I like that there are sympathetic characters within the organization, and the mystery about the murder and the secret interests me. Also, I’ve somehow actually begun to like Ganju, who I disliked in volume 10 and merely tolerated in volume 11. How did this happen?