Glenn (left) and Rick (right) wear zombie guts in downtown Atlanta to disguise the fact they're human.

Atlanta: more zombies are on the way.

After its monstrous opening of 5.3 million viewers last Sunday, AMC’s “The Walking Dead” was virtually a lock for a second season.

But AMC waited until the numbers came in for the second episode last night: 4.7  million viewers. That’s close to 90 percent retention, which is excellent, especially after all the hype for the debut episode. That meant the initial viewers liked what they saw and came back for more.

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The zombie drama, shot in metro Atlanta this past summer with a modest six-episode opening season, also did well internationally, another major consideration for any show to get renewed.

Of those 4.7 million viewers last night, 3.3 million were in the target 18 to 49 year old demographic. The second episode actually drew more 18 to 49 year old men than the first one: 2.1 million vs. 2 million, according to Nielsen numbers compiled by Deadline Hollywood.

The show will get 13 episodes. No word on when production will start but my guess is they’ll probably get going early next year when it’s a wee bit cooler.

Last night’s episode focused primarily on actions on the rooftop of a downtown Atlanta building and included two characters slathering themselves with zombie guts to disguise themselves from the actual zombies. Yum! Next week: a reunion that includes some awkward elements and a need to go back into downtown Atlanta to get a cache of weapons Grimes  left behind.

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