Supernatural season 10 spoilers: Episode 20-22 synopsis out; will Dean go on a rampage again?

The last three episodes of Supernatural season 10 promise some epic moments for Sam and Dean Winchester.

All through season 10, fans have seen Dean's condition deteriorate because of the mark of Cain. And Sam has bent over backwards to find a cure for his brother. In the previous episode we saw, Sam forming an unlikely alliance with Rowena, who agreed to find a cure by decoding The Book of the Damned. Post which, Sam agreed to kill Crowley the King of Hell, to keep his side of the bargain.

In the season 10 finale episode titled My Brother's Keeper, which will air on 20 May, Death will pay another visit to the Winchester brothers, according to leaked spoilers.

Here is what we can expect in the next three episodes.

Episode 20, Angel Heart, will air on 29 April.

The official synopsis reads as follows:

When Claire Novak (guest star Kathryn Love Newton) gets a lead on her mother, Amelia (guest star Leisha Hailey), who has been missing for years, Castiel (Misha Collins) asks Sam (Jared Padalecki) and Dean (Jensen Ackles) to help her. Castiel feels guilty for what he did to the Novak family and wants to make amends by reuniting Claire with her mom. However, when they find out what took Amelia, they realize there is a chance Claire may not get her happy ending.

Episode 21, Dark Dynasty, will air on 6 May.

The official synopsis reads as follows:

The Winchesters meet The Stynes. Dean (Jensen Ackles) and Sam (Jared Padalecki) investigate a bizarre murder and realize the killer bears the same tattoo as those from the Styne family. Eldon Styne (guest star David Hoflin) attacks Dean and a brutal fight ensues. Meanwhile, Castiel (Misha Collins) acts as referee when Charlie (guest star Felicia Day) and Rowena (guest star Ruth Connell) are forced to work together on the Book of the Damned. Crowley (Mark Sheppard) discovers his mother is missing and knows she's up to something so he turns to an old enemy for help.

Episode 22, The Prisoner, will air on 13 May.

The official synopsis reads as follows:

Dean is on a rampage. When it comes to the Stynes, Dean (Jensen Ackles) decides to take matters into his own hands. Sam (Jared Padalecki) tries to come to terms with his decision.

Supernatural airs every Wednesday at 9pm on The CW.