S9·E11 First Born

Episode recap

Task: Write a 280-380 word episode recap for Supernatural S9E11 (First Born).
Constraints:
Use ONLY verifiable facts from the provided SYNOPSIS and SOURCES.
No invented titles, names, dates, counts, awards, ratings, etc.
No guessing or inventing plot points.
Original, neutral, encyclopedic prose.
Plain text ONLY (no markdown, no asterisks, no headings, no bullet points).
Word count target: 280-380 words.
Synopsis: Crowley turns to Dean for help to locate the First Blade, the only weapon that can kill Abaddon. The trail leads them to the biblical Cain. Meanwhile, Sam asks Castiel for help when they need to extract the remaining angel grace from Sam's body to track Gadreel.
Sources:
[1] TMDB: Series title, genre (Drama, Mystery, Sci-Fi & Fantasy), tagline.
[2] Wikipedia: Creator (Eric Kripke), network (The WB, The CW), seasons (15), dates (Sept 13, 2005 - Nov 19, 2020), main characters (Sam played by Jared Padalecki, Dean played by Jensen Ackles).
[3] IMDb: Creator (Eric Kripke), cast (Jared Padalecki, Jensen Ackles, Jim Beaver, Misha Collins), premise (brothers follow father's footsteps as hunters).
[4] ČSFD: General commentary (not useful for plot).
[5] Netflix: Streaming info (not useful for plot).
Plot points available:
Crowley asks Dean for help finding the First Blade.
The First Blade is the only weapon that can kill Abaddon.
The search leads to Cain.
Sam asks Castiel for help.
The goal is to extract remaining angel grace from Sam's body.
The purpose of extracting grace is to track Gadreel.
Character/Actor info available:
Sam Winchester (Jared Padalecki).
Dean Winchester (Jensen Ackles).
Castiel (Misha Collins).
Crowley.
Abaddon.
Cain.
Gadreel.
Constraint Check: The synopsis is very short. The word count requirement is 280-380 words.
Problem: The provided synopsis is only about 50 words. To reach 280-380 words using only the provided facts without inventing anything is mathematically impossible if I am to remain "meticulous" and "never invent or guess."