Sweet low miles acquisition... Rear brake cooked where to start (03' 1800s)

So I came across this 2003 1800s with only 12,500 miles. Couldn't pass her up. But the rear brake is completely non functional. Just goes to the "floor" with zero brake power. I haven't been able to look at it yet, but my sense of it is that the fluid leaked out or something. Can anyone help get me started? Probable issues? What do look at first? Any help would be appreciated.

u/CaptianBrasiliano — 29 days ago