'Supernatural' season 12 spoilers: A prison breakout, a 'Memento'-type Dean, and more British Men of Letters are coming in 2017

More bizarre and interesting things are up ahead when "Supernatural" season 12 returns in 2017, assuming that that the Winchesters do make it out of a high-security prison alive.

The next episode of The CW's long-running fantasy series will send Castiel (Misha Collins) and Winchester matriarch Mary (Samantha Smith) on a quest to find the undisclosed government prison where Sam (Jared Padalecki) and Dean (Jensen Ackles) were taken following their arrest in the show's midseason finale. Titled "First Blood," the episode is also expected to shed some light on the Winchester brothers' seemingly intentional will to get imprisoned.

What obstacles will Castiel and Mary encounter in their rescue mission? Will allies Crowley (Mark A. Sheppard) and Rowena (Ruth Connell) lend a helping hand? Were they in on the Winchesters' plans, or have they secretly concocted a plan of their own? Will the outcome of this rescue mission somehow affect the hinted storyline of an upcoming episode?

Executive producer Andrew Dabb recently shared some details on Dean's rumored de-aging in episode 11 via TV Line. Dabb said that the older Winchester will be experiencing a regression that is more cognitive than physical.

"He will be trapped in a "Memento"-type loop, where he's kind of losing his memory a little bit," Dabb teased, further adding that the condition will be somewhat freeing for Dean who has been struggling with a lot of personal baggage through the years. He will be acquiring a more "fun and childlike" disposition, but that things will quickly turn tragic on an emotional level when he starts forgetting Sam as well as himself.

Meanwhile, executive producer Robert Singer told Entertainment Weekly that Mr. Ketch (David Haydn-Jones) and the rest of the British Men of Letters will be playing a much bigger role in the back half of "Supernatural" season 12, following their much needed assistance in the upcoming episode 9.

Will they be instrumental in helping the Winchesters escape prison? Could they have already gotten wind of Lucifer's spawn and taken care of it without hesitation? Will they be a true ally for the Winchesters and their crew, will they end up as enemies when their differing principles begin to clash?

"Supernatural" season 12 returns at an earlier timeslot on Thursday, Jan. 26, at 8 p.m. EST on The CW.