'Supernatural' season 12 return date, spoilers: Multiple Castiel-centered episodes up ahead; Dean to gradually lose his memories

A "Memento"-inspired episode is up ahead when "Supernatural" season 12 returns next year.

The back half of season 12 will continue to explore interesting cases, and an upcoming episode will see Dean (Jensen Ackles) slowly losing his memory. According to executive producer Andrew Dabb, the season's 11th episode will see the elder Winchester brother "trapped in a Memento-type loop, where he's kind of losing his memory a little bit."

Considering the Winchesters' difficult job of solving supernatural cases, Dabb teased that it will soon affect Dean's memory in some way. "You're going to see a Dean that is a lot more fun and childlike. Jensen [Ackles] does a great job," he said. "Then it becomes a much more tragic story as he starts to forget Sam — and himself," the EP added.

Meanwhile, Castiel (Misha Collins) will also take center stage in future episodes. Dabb notes that "at least three really strong Castiel episodes" are coming up, focusing on the angel's backstory, starting with an episode that will be airing on Feb. 2. As fans know, Castiel was watching over Earth before he eventually came down to rescue Dean in hell. The latter half of season 12 will explore that time of his life along with a lost story from his past. The next episode which is centered on Castiel will introduce his old foe, Lily Sunder, who will be played by "The Walking Dead" actress Alicia Witt.

The EP admits that giving Castiel, along with the other main characters, their due while tackling Lucifer's search for a new vessel has been a tough balancing act. "I think we did a fairly good job of keeping Crowley alive [and] keeping Castiel alive, but the new characters certainly ate up a little space," Dabb told TV Line. He added that cramming a huge storyline in just eight episodes proved to be difficult, but things will change when the show heads to its winter premiere. "We have a lot more room to play," he continued, adding, "Those characters are going to come to the fore a lot more."

The 12th season of "Supernatural" returns to the small screen on Thursday, Jan. 26, at 8 p.m. ET on The CW.