When we last spoke with Vince Gilligan, the creator of “Breaking Bad,” he told us he wouldn’t start planning the final season of that show until mid-November. In the meantime, it looks as if some of his AMC colleagues have some thoughts about how that series might continue past the end of the world.

In a scene from Sunday’s episode of “The Walking Dead,” that network’s hit zombie-apocalypse drama, Daryl, a salt-of-the-earth survivor played by Norman Reedus, produces a bag of drugs that belongs to his missing brother, Merle, and begins to rhyme off an inventory of its contents: crystal meth; ecstasy; painkillers; some first-class doxycycline (Merle, it seems, dealt with the occasional bout of the clap.) We’re given only a glimpse of the bag, but we can see that the crystal at its bottom is a certain shade of blue — the same color it takes on when it is cooked by Walter White, the “Breaking Bad” drug-lord-in-training played by Bryan Cranston.

In a portion of AMC’s “Walking Dead” after-show, “Talking Dead,” that was posted online, Robert Kirkman, a creator of the “Walking Dead” comics and a producer of the television series, said that the inclusion of the blue meth was indeed “a little Easter egg we were doing for AMC fans.”

Asked by the “Talking Dead” host Chris Hardwick if Walter White had survived the zombie apocalypse, Mr. Kirkman said, “I would say so. I think that guy could survive anything.” He that his television show needed to get “some well-dressed ‘Mad Men’ zombies.”

It’s not immediately clear how crystal meth that is cooked in Albuquerque would make it all the way to Atlanta (carried over by an industrious zombie, no doubt). But it wasn’t be the first time these two AMC shows have collaborated: KNB EFX, the special effects company of the “Walking Dead” co-executive producer Greg Nicotero, helped design a memorable scene for the “Breaking Bad” finale, featuring a character who can make return appearances only in flashbacks or as a member of the undead.