WARNING: The following article contains spoilers for "Unknown Factors," Episode 21 of Young Justice: Outsiders, streaming now on DC Universe.

As the hype around blockbuster movies and television series increases, the more they utilize the ever-popular "post-credits scene." Although they've been around for decades, most fans will acknowledge 2008's Iron Man as the starting point for the technique's current popularity. The DC Universe streaming service has recently employed such stingers to set up the second season of Titans and to close out Swamp Thing.

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Perhaps then it shouldn't be too much of a surprise that Young Justice finally delivered its first post-credits sequence this week. "Unknown Factors" may not be the Season 3 finale, but it does set up a new threat by mentioning one of the most powerful weapons in the DC Universe.

The scene opens on the home of Gretchen Goode, the civilian identity of Granny Goodness on Earth, where she's founder of Goode World Studios. Earlier in the episode, Nightwing and Black Lightning broke into her home in a recon mission, only to be captured and brainwashed. The duo is rescued in an intervention by Aquaman (Kaldur'ahm), his partner Wyynde, Beast Boy, Geo-Force, Cyborg and Halo.

A red light can be seen through the windows of Gretchen's home. Down on one knee, Gretchen says to someone off-screen, "Good news, sire. Tonight, I found the Anti-Life Equation." It's here we see the red light is a hologram of Darkseid, ruler of Apokolips. After Gretchen's update, the camera zooms in for a close-up of Darkseid's squinty eyes as the screen goes to black.

Darkseid and Apokolips have been a background presence for much of Young Justice: Outsiders, after Season 2 concluded with a nefarious handshake between Darkseid and Vandal Savage. Episode 7, titled "Evolution," also documented the first meeting between the villains in the early days of the DCU. So even though the metahuman-trafficking epidemic has been the central focus of the third season, Darkseid has lurked in the shadows.

The Anti-Life Equation is one of DC's most powerful, and dangerous, weapons. The comics have long portrayed Darkseid's obsession with gaining possession of the Anti-Life Equation, and its ability to grant a user anything from control over sentient beings to dominion over the cosmos.

Of course, there were clues dating back to January that Young Justice: Outsiders would introduce the Anti-Life Equation. Eagle-eyed fans were able to decode the first letters of Young Justice: Outsiders' 26 episode titles to read, "PREPARE THE ANTI-LIFE EQUATION." This post-credits scene confirms the series is preparing to introduce the formula, officially.

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The Anti-Life Equation has played a part in previous DC television series. For example, the final episode of the fan-favorite Justice League Unlimited featured Darkseid and his Apokolips forces invading Earth. Right before Darkseid has the opportunity to kill Superman, Lex Luthor presents to him the Anti-Life Equation, which conveniently fits in the palm of his hand and is represented by a glowing light. Luthor and Darkseid both disappear with the Equation; some heroes believed they died while skeptics anticipated their eventual return. The live-action Smallville also included references to the Anti-Life Equation.

Right now, all clues point to the Outsider Halo as being the key to finding the weapon. When Halo removes Overlord's brainwashing of Black Lightning and Nightwing, Gretchen comments that she recognizes the ancient language spoken by Halo, who has the spirit of a Mother Box inside her. Gretchen may believe Halo possesses the Anti-Life Equation, or at least has an idea on how to find it.

With only five episodes remaining, there is a good chance we'll get to see if Gretchen is correct.

New episodes of Young Justice: Outsiders premiere Tuesdays throughout the summer on DC Universe.

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