I'm surprised to see this arc come to a close so quickly, setting some other plot points to extend out into the next arc or so. The siege of the Coral City Police department wrapped up surprisingly quickly, especially since half this issue is dedicated to fleshing out character backstories. But in the context of the whole series, the point they're at now isn't exactly unreasonable. I like that we're getting the full story on each character (save Vengeance Moth and Virtue), it just comes at a weird time, right at the first big climax; and so it reduces the page space there was for the big climax.
Despite interrupting the big climax a bit, I feel like the backstories came at the right time. We've been adventuring with these people and getting to know them, but it's good to finally see how they all got there before their first big tale wraps up. The flashbacks are actually woven into the flow of the narrative surprisingly smoothly. Mouse is an absolutely fascinating specimen, and a likely nod to a VERY controversial group of people. Katharisis is about what I expected, but it was nice to finally get the details. Burden was pretty much what we knew, but the details make his childhood experiences even more harrowing and twisted. The biggest surprise was in Tremor's backstory, but but in the present it's resolved way too quickly considering we just discovered it.
In Conclusion: 4/5
This may essentially be the end of an arc, or at least a major plot point too soon, but all that means for this series is that the stakes are HIGHER, the tension is greater, and things are about to get a whole lot more dangerous. There's no turning back for The Movement now.