Spoilers from E!Online. Jim tweeted quite a bit during the filming of the zombie ep:
* Long, difficult, weepy day. Another one in a few hours. I love my job.
* Shooting a great scene today. Long. Touching. Heartbreaking. Difficult. Thankful for it.
* Shooting people who are already dead...seems redundant but sometimes it's necessary.
Yay! Zommbies and Bobby backstory!
Also am excited/scared about Sam using his powers again.