Just in: AMC has issued a speedy renewal for zombie drama The Walking Dead after Sunday's second episode averaged 4.7 million viewers, a small 11% drop from the 5.3 million who tuned in for the 90-minute premiere on Halloween, reports USA TODAY's Gary Levin.

The network ordered 13 new episodes of Dead, based on the comic-book series by Robert Kirkman, due next year. The current six-episode first season will run into early December. Dead is AMC's biggest original series, doubling the average of AMC's other scripted dramas, Breaking Bad and Mad Men, and performing especially well among young-adult viewers.