The Title changed to “The Song Remais The Same“
Anna will be back in this episode. We’ll find out what happened after Castiel turned her in last season.
Anna will go back in time from 2020 to 1978 to kill John and Mary Winchester before Dean and Sam were born, then Sam won’t say yes to Lucifer. Sam and Dean go back in time as well to save their parents. When they find them this time, they’re newlyweds and living in an apartment, and John’s trying to wrestle with keeping his job. It’s just interesting seeing little snapshots of what their family was like before the boys were born.
Sam seeing his parents is heart-wrenching—particularly his mom, because she died when he was just a baby. When he first meets her, he’s so overwhelmed he can’t even speak. But the most heartbreaking story is Mary’s. She’s done everything she can to leave hunting behind and have a normal life with John. But as the episode unfolds, we see her realize she can never escape.
According to The CW the title of this episode will be “Back to the Future II“