“Supernatural” is slowly but surely building towards the Season 12 finale. Last week on The CW series, Dean (Jensen Ackles) and Sam Winchester (Jared Padalecki) tried to help twins Alicia (Kara Royster) and Max (Kendrick Sampson) find their mother Tasha (Alvina August) who hadn’t checked in on them for a week while hunting in Wyoming.

Worried about her mother, Alicia called Mary (Samantha Smith) for help. Unfortunately, Mary was busy working with Mr. Ketch (David Haydn-Jones) in order to find the location of a shifter’s family. Instead, Sam and Dean helped Alicia and Max. Sadly, “Supernatural” Season 12, episode 20 ended on a tragic note with the murder of Tasha and Alicia.

Even worse, Max decided to carry the burden of a witch that derived her powers from making a deal with a demon. He now has a deal with the demon and, in exchange, he gets to keep his sister’s memory alive in a body made entirely of twigs.

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Meanwhile, Mary discovered that Ketch has been spying on her sons and killing innocent supernatural creatures.

What will happen this week on “Supernatural”?

British Men of Letters (BMOL) members Lady Toni Bevell (Elizabeth Blackmore) and Ketch will continue to hold Mary as their prisoner. However, the upcoming episode will build towards a showdown between Mary and Toni. After all, mama Winchester is smart enough to beat them and escape captivity.

According to the synopsis of Season 12, episode 21 on TVGuide, Toni will face off against Mary. Meanwhile, Sam and Dean will discover that hunters all over the country are being killed in suspicious accidents. Of course, the BMOL are behind staging these so-called accidents.

Naturally, Mary’s boys will be worried about her. They will try to find her just to make sure that she is safe. But Mary isn’t safe.

The promo of episode 21, suitably titled “There’s Something About Mary,” shows Sam devastated to learn that hunters are being killed.

The video also shows a glimpse of Lucifer (Mark Pellegrino) who is still Crowley’s (Mark Sheppard) prisoner. The devil has been trying to escape and reunite with his unborn child and Kelly (Courtney Ford). Kelly is carrying his baby and Castiel (Misha Collins) is protecting her and Satan’s son. Hopefully, we will get an update on Kelly and Lucifer this Thursday.

It’s also high time that the fallen angel somehow escapes his shackles in hell and outsmarts Crowley.

Perhaps the death of several hunters is what propels Sam and Dean to become leaders of their community and fight the BMOL in the Season 12 finale. The two-hour final episode of the season will focus on the American hunters’ fight against the British supernatural-fighting organization and the birth of Lucifer’s baby.

There are only two episodes left for “Supernatural” to wrap up its current season. The season finale premieres next Thursday, on May 18.

“Supernatural” airs Thursdays at 8 p.m. EDT on The CW.