Now, we all know that Governor is waiting outside the prison and spying on them.
We also know that Michonne & Herschel are going on a run/outside the prison ( I think )
And finally we know that - Comic Spoiler
So, this is my prediction for what will happen to Michonne & Herschel
I think the scene at the end of episode 5 heavily points to this happening and it's a pretty huge moment from the comics so there's a good chance they will want to include it in the tv series and this does some like the most realistic way to make it happen.