Volume 12. The serial nature of the story has advanced still farther, with more and more story flowing between the tales -- so spoilers ahead for the earlier ones.
Indeed, you can still hear the Doom Bell from the end of the Hammerless Bell at the opening, and it determines much of the opening sequences. It's in this book that Mama Gkika notices, for instance, that Gil is unaffected by the bell's ringing in the midst of their polite conversation about how the Baron protected the jaegers and the jaegers served him loyally, which they will not forget now that the
Despite its heavy impact on the invading forces, there's a lot of clean-up to be done. Both of the invaders and of the town itself. The arrival of the jaegers in force. When Moloch and his band are recognized as the prisoners, he retorts that's what they were -- now, they are a heroic band of traveling repairmen! And, of course, the problem of the empire over all, with the destruction of the hospital. Agatha gets briefings on history and starts to lay plans.
Gil leaves the town to return Castle Wulfenbach, where -- after a funny sequence of getting through the guards to the control center including punching out a guard while saying he will promote him (the only guard who thinks to question his evidence of identity -- he is immediately, on his father's orders, recognized as the new Baron. (The scene where Bang explains why she was not at the hospital when it happened has a surprising but very effective twist.) And he meets Tarvek again, furiously making plans. When Klaus reappears and orders their capture, Gil leads the way -- and gets Tarvek out.
It involves another falling machine, Zeetha's lecturing Agatha about needing to know how a princess behaves -- practical details starting with the observation that every princess needs a battle axe -- the point at which Moloch's resolution to flee Mechanicsburg as soon as he can walk is undermined, the use of an actual ram on the gates (it lowers its head and butts), Tarvek's making a better impression on the jaeger generals than Krosp did through powers of observation, a battle between dragons, a heroic rescue of weasels and notes, a jaeger whose father was a philosopher (trust me, after years of listening to him, you too would want to burn down the world), and much more.
And as it begins, so does it end: with a dramatic turn in the story, without showing its impact. That's next volume. (Or online.)
I was particularly taken by the witty conversations that peppered it all.