Speaking at a TV Academy panel in Los Angeles, Mazzara confirmed that he had just finished work on the script for the episode and dropped a few hints about its content, according to The Hollywood Reporter.
Mazzara said: "It's pretty dynamic and action-packed with tons of zombies, but also a lot of quieter moments and a lot of heart.
"This is a group of survivors, a family that has come together and they have no good options, no place to go and they're really trying to keep themselves alive, and keep each other alive.
"You can see how desperate they are; they're clinging to each other. It's those moment of human interaction and heart that are important."
Kirkman implied that the season would be a good one for fans of the original comic series, saying: "For comic fans, they know the good stuff is coming. The really intense stuff with Michonne, the Governor and Woodbury [prison] really defined the comic book series and we haven't even gotten to that stuff yet.
"Now that we're getting to that stuff in season three, it's really going to change the show quite a bit."
Kirkman went on to get slightly more specific, teasing that a memorable moment from the comic book series will feature in the premiere, but that it will involve a different character than the comic's version.
He teased: "There will be cases where something memorable... will be displaced and given to somebody else.
"I'll hint that that actually happens in our first episode back in season three - something memorable that happened to a character in the comic is happening in the show in our first episode back, and it's not the same character."
The show's third season will be set in the town of Woodbury, it has been confirmed.
Lauren Cohan will become a series regular for the third season.
The Walking Dead will return to AMC later this year, and airs on FX in the UK.
Watch a trailer for the upcoming video game based on the series below: