True Believers takes place a little while after Volume 3 and finds the runaways together again and helping stop crime now that the Pride doesn't control the city anymore.
I still enjoyed this series, though the introduction of other characters made me consult wikipedia to learn a bit more about them.
Unfortunately this is the last one available on kindle. I found reading graphic novels on my kindle fire to be easy so I've been loading up on a fair amount of them. :)