Supernatural will bring back the Winchesters' long-lost brother at last.

According to TVLine, Jake Abel's Adam will return to the series alongside several other characters, including God’s sister Amara and Shoshannah Stern's Eileen.

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Adam, of course, is Sam and Dean's half-brother. He was born to Kate Milligan, a nurse who ran into John Winchester after a hunt left him injured. In Season 4, a ghoul disguised as Adam reached out to John in an effort to trap and kill him. Since John had died, Sam and Dean answered the call. Neither Adam nor Sam and Dean were aware the other existed. By the time the Winchesters realized who Adam was, it was too late; he had already been killed by the ghoul.

In Season 5, Adam was returned to life to play a pinnacle role. The angels convinced Adam to become the vessel for the archangel Michael, who was destined to defeat Lucifer and usher in the end of days. When Sam threw himself into Lucifer's cage, disrupting the prophecy, Michael followed Lucifer back to hell. This trapped both Michael and Adam in Lucifer's cage, where they stayed -- until now.

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Season 15 will find the Winchester brothers experiencing "an existential crisis." "They’re realizing, ‘Well, we’re the Winchesters, but were we really doing this Chuck’s way?'" co-showrunner Andrew Dabb teased. “Part of reclaiming that agency is a big part of the season for them.”

Indeed, Sam and Dean will "lose people who, in past seasons, we would’ve never lost -- and lose them in a very real way. Our guys are going to realize there’s a certain finality, and some of the things they’ve relied on to get through the day -- people, talents, things like that -- they are no longer going to be able to roll out. And that’s going to throw them for a loop."

Returning Thursday, Oct. 10 at 8 p.m. ET/PT on The CW for its final season, Supernatural stars Jensen Ackles, Jared Padalecki, Misha Collins and Alexander Calvert.

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