We have the synopsis for episode 12
 
SUPERNATURAL
“Prophet and Loss”— (8:00-9:00 p.m. ET) (Content Rating TBD) (HDTV)


NO LOOKING BACK – Sam (Jared Padalecki) and Dean (Jensen Ackles) must figure out how to stop the bloodshed when Donatello (guest star Keith Szarabajka), who, in his current condition, is inadvertently scrambling the order of future prophets. Nick (Mark Pellegrino) comes face to face with his past. The episode was directed by Thomas J. Wright and written by Brad Buckner & Eugenie Ross-Leming. (#1412). Original Airdate 1/31/2019.

Source:

The CW

 
So Donatello is able to affect the world. I guess Cas didn't brain wipe him? How is is scrambling the order to future prophets? What is in Nick's past? let us know in the comments or in the discussion thread for episode 12.