Well, seems like we were hacked.
I reached out to the guy, but he's still to reply. Hopefully he will!
In the meantime, I think I identified the hole he exploited, and patched it. We'll see though ...
No passwords were stored in plain text, but the hacker claims (and showed) cracked passwords from the forum accounts.
The site passwords are safe, I think, but we can't be sure.
The hacker seems friendly, and hopefully he'll just help us improve our security. In any case - just to be on the safe side - change your password(s) on Next Episode (and if you use the same password anywhere else).
Update: There is an update in the forum thread. In short - we're good and your site password is safe.