Call of Duty: Black Ops 3's most recent expansion--Descent--just released last month, but Treyarch senior executive producer Jason Blundell has already started teasing the contents of the fourth and final DLC pack, which will launch later this year.

Most significantly, "DLC 4" will provide the last installment of the long-running Zombies storyline that originated back in 2008's Call of Duty: World at War. As the final expansion for the final Black Ops game, Blundell hopes to "put brackets around" the experience by wrapping up the ongoing story.

Naturally, this means resolving old cliffhangers. During a recent interview with GameSpot, Blundell explained, "At the end of Black Ops 2, I think I enraged the community some when I put in this video that showed Samantha in a house with a boy called Edward. They were playing with zombie toys. Then an alarm goes off and you hear Max's voice calling them down to the basement. The characters say, 'I wish our heroes in our stories were real.' Then we dropped to black. That was the end of Black Ops 2. People lost their s***."

Blundell continued: "I've still technically to this day not answered that question of what that was and why that was there. That will be answered by the end of DLC 4. I believe that the ending of DLC 4 will spark emotion in the players, which is my goal. It's not out of the desire for trolling, as people say. No, what I want to do is have you have complex and differing thoughts on what you've experienced and what your view is. I hope that's what we generate when we come to the end of DLC 4."

If you're wondering what in the world Blundell could be talking about, chances are you're not alone. According to him, the Zombies development process is incredibly secretive--even internally.

"It's a very tight group. Essentially I'll have my gameplay director in the room, I have my lead writer, and it's me. That's it," he said. "We have a level of paranoia which is probably unhealthy actually. There's just so limited information that we share, either out on the floor or through Activision. We keep it quite tight-lipped. First of all, it's crazy and we don't want them to put us in insane asylums. But second of all, just to control the information about the kind of craziness that we do."

Regardless of the specific nature of the craziness contained within it, we expect Black Ops 3's DLC 4 to release before the end of the year--most likely prior to the launch of Infinity Ward's Call of Duty: Infinite Warfare in November.