We have the synopsis for episode 20.
Twigs & Twine & Tasha Banes” — (8:00-9:00 p.m. ET) (Content Rating TBD) (HDTV)

RICHARD SPEIGHT, JR. DIRECTS – Alicia Banes (guest star Kara Royster) calls Mary (guest star Samantha Smith) for help after her mother, Tasha (guest star Alvina August), goes missing. Sam (Jared Padalecki) answers Mary’s phone and he and Dean (Jensen Ackles) head out to help Alicia and her twin brother, Max (guest star Kendrick Sampson), find their mother who was hunting a powerful witch. Meanwhile, Mary starts to have some doubts about the British Men of Letters. Richard Speight, Jr. directed the episode written by Steve Yockey (#1220). Original airdate 5/4/2017.
The Barnes twins are back! I hope they survive the episode. Mary finally is getting a clue about the BMOL. What do you think? Are you glad to see the twins again? What clues Mary in about the BMOL? Tell us your thoughts in the comments or in the discussion thread for episode 20.