When The Walking Dead returns on Sunday, viewers should be expecting chaos. All of the buildup from the first half of season six comes to head and explodes.

However, looking ahead, it sounds like The Walking Dead is only just getting started with its chaotic midseason premiere. More specifically, The Walking Dead's season finale sounds like it will be one of the most difficult episodes to stomach of the entire series and fans are largely expecting it to mark the arrival of Jeffrey Dean Morgan's Negan.

“I felt sick to my stomach when I read the script," Rick Grimes actor Andrew Lincoln tells EW of the season six finale. "It was the first day in the whole six years of working on The Walking Dead that I was late for work because I woke up in the middle of the night and I couldn’t get back to sleep. I was so angry and frustrated and I felt sick. And that was just after reading it.” Lincoln might not be happy about the episode but Lauren Cohan seems to be taking it especially hard.

“[Hearing] the word ‘finale’ gives me a physical reaction because it’s the hardest day on set that I’ve ever had in my life,” says Cohan. “I never even imagined that as an actor you could have that experience. It’s one of the most raw experiences that I think any of us have ever had. Andy talks about being late to work; I didn’t want to go to work that day. It took a really, really long time for everybody to feel okay again after the finale, let’s put it that way.” Spoiler Warning: If The Walking Dead's season finale is anything like issue #100 of its comic book source material, it will be just as "emotionally wrought" as Ross Marquand promised it would be when we talked a few months ago. To recap, upon Negan's arrival, he unleashes his barbed wire wrapped baseball bat on Glenn's skull. There's no word on whether or not the TV series will follow the same series of event.