Someone on /a/ posted a summary of the Drama CD that came with BD vol. 1. It's apparently set during Timeline 1 of episode 10 and goes a little in-depth and expands to what happened during that timeline. Not sure if its legit, but it seems so. Heres a link to the thread: http://boards.4chan.org/a/res/48664832#48666058
If this summary is legit, apparently the black cat from the OP is relevant!