"Supernatural" is getting prepared for its mid-season finale, and from what we know of the writers from the last ten seasons, it is going to be one amazing ride. In fact, Season 11 Episode 9 will bring back one popular character we have all wanted to see for a while; Lucifer (Mark Pellegrino).

In the last few of episodes Sam (Jared Padalecki) has been getting visions, that he assume are form God, and they show him Lucifer's cage. Fans will remember that Sam himself was stuck there for a while after he pushed himself along with Lucifer into the cage following "Swan Song".

We also know that even after he got back, Sam struggled to get back to his former self, and was plagued by Lucifer's presence wherever he went. The fallen angel kept taunting him and made his life miserable. It took a lot of effort on Dean's (Jensen Ackles) part to save his brother again.

However, now it looks like Sam will have to re-visit his worst nightmare and visit the cage again. We also see the return of Crowley (Mark A Sheppard) in the promo for "O Brother Where Art Thou?" and he is seen telling the Winchesters that "there may be a way".

Crowley has been MIA since his disastrous stint at being a foster father to Amara (Samantha Isler), even avoiding calls from Dean. He still looks disturbed, but it looks like he has learned that he cannot control the Darkness on his own and need to help the brothers lock her back in her cage.

The promo ends with Lucifer claiming triumphantly, "I am their only hope". So, after months of speculation, it can be confirmed that Lucifer will be returning to the show, and what a great dynamic it will be to have Lucifer working with the boys, instead of against them.

The last we saw him, Lucifer was the greatest villain there ever was, and now someone worse than him has appeared. There is no end to evil with "Supernatural", which is what makes it one of the greatest shows even after ten seasons.

Watch out for Season 11 Episode 9 of "Supernatural" at 9.00 PM (EST) on Wednesday, 9 December. You can also live stream "O Brother Where Art Thou?" via CWTV.