Off the top of my head...

!SPOILERS! !SPOILERS! !SPOILERS!

There's a new group in the prison that includes a major character from the comic, Tyrese. Little Carl saves them and brings them back to their part of the cell block, but separated from the group.

Michonne and the group rescues Maggie and Glen, but separates herself from the group to get her revenge on with the governor. She kills Penny, pokes out one of the the governors eyeball out, and is then confronted by Adrea who lets her go.

I think after Penny's death, we're going to see the Governor become totally unhinged and let his inner evil all hang out.

Oscar bites the dust. Rick shoots some guy who he thinks is Shane, until he realizes its some random dude. Michonne more or less wants to be a part of the group and tells Rick that they need her. Daryl covers the group's escape but gets caught in the end.

The prisoner guy that got left behind (guy with mustache) perv's out on little Beth. You can see Carl getting protective over Beth. Carol tells mustache guy to not go near Beth again. At one point she declares to him that she's not a lesbian.

In general, you see Carl really stepping up this episode as trying to take care of the group thats left behind at the prison.

The Governor declares Daryle a terrorist that attacked Woodberry and pegs Merle as an inside accomplice to the attack. Governor was pissed about finding out that Merle lied to him when he was told that Michonne was dead, and it cost him an eye.

One of the last shots is Adrea recognizing Daryl.

I'm sure I left a thing or two out. I'll update as I remember <img src="/ubbthreads/images/graemlins/smile.gif" alt="" />