S10·E10 The Hunter Games

Episode recap

Task: Write a 280-380 word episode recap for Supernatural S10E10 (The Hunter Games).
Constraint 1: Use ONLY verifiable facts from the provided SYNOPSIS and SOURCES.
Constraint 2: No inventing/guessing titles, names, dates, counts, awards, ratings, numbers, or plot points.
Constraint 3: If a detail is not in the material, omit it.
Constraint 4: Write original, neutral, encyclopedic prose in plain text.
Constraint 5: No markdown, no asterisks, no headings, no bullet points.
Constraint 6: Word count target: 280-380 words.
Synopsis: After the massacre at the ranch, Dean, Sam, and Castiel double their efforts to find a cure for the Mark of Cain. Desperate, Castiel comes up with an idea that Sam deems the single worst idea he's ever heard. Meanwhile, Rowena continues to plot against Crowley.
Sources:
[1] TMDB: Series title Supernatural (2005).
[2] Wikipedia: Series aired on The WB and The CW for 15 seasons (Sept 13, 2005 - Nov 19, 2020). Stars Jared Padalecki (Sam Winchester) and Jensen Ackles (Dean Winchester).
[3] TMDB Cast/Crew: Sam and Dean Winchester lost their mother to a demonic force; father raised them as soldiers.
[4] Simple English Wikipedia: Created by Eric Kripke. Stars Jared Padalecki (Sam Winchester) and Jensen Ackles (Dean Winchester).
[5] Moviefone: Sam and Dean Winchester lost mother to demonic force; father taught them to kill paranormal evil.
Episode: S10E10 (The Hunter Games).
Context: Following a massacre at the ranch.
Characters involved: Dean, Sam, Castiel, Rowena, Crowley.
Plot point 1: Dean, Sam, and Castiel are working to find a cure for the Mark of Cain.
Plot point 2: Castiel proposes an idea that Sam considers the worst idea he has ever heard.
Plot point 3: Rowena is plotting against Crowley.
The synopsis is very short. The sources provide general series info but nothing specific to the plot of S10E10 other than the synopsis itself.
The word count requirement is 280-380 words.
Problem: The provided synopsis is only about 45 words. If I strictly follow "Use only supplied facts" and "If the synopsis is sparse, stay concise rather than guessing," I cannot reach 280 words without inventing information