We have the synopsis for the finale of season 14 of Supernatural.
 
SUPERNATURAL
“Moriah”— (8:00-9:00 p.m. ET) (Content Rating TBD) (HDTV)


ALL HELL BREAKS LOOSE ON A SHOCKING SEASON FINALE – Sam (Jared Padalecki), Dean (Jensen Ackles) and Castiel (Misha Collins) are thrown into an epic battle. Meanwhile, Jack (Alexander Calvert) becomes disenchanted with all the lies, and an old friend from the past shows up. Phil Sgriccia directed the episode written by Andrew Dabb (#1420). Original airdate 4/25/2019.

Source:

The CW

 
 Who is the epic battle with? Which lies has Jack become disenchanted with? Who is the old friend. Give us your thoughts in the comments or in thediscussion thread for episode 20